diff --git a/toolchain/check/handle_alias.cpp b/toolchain/check/handle_alias.cpp
index 237c5dcce9bed..d925e420f9995 100644
--- a/toolchain/check/handle_alias.cpp
+++ b/toolchain/check/handle_alias.cpp
@@ -16,11 +16,6 @@ auto HandleParseNode(Context& context, Parse::AliasIntroducerId /*node_id*/)
     -> bool {
   context.decl_introducer_state_stack().Push<Lex::TokenKind::Alias>();
   context.decl_name_stack().PushScopeAndStartName();
-
-  // Push a pattern block to handle parameters of the alias declaration.
-  // TODO: Disallow these in parse, instead of check, so we don't have to do
-  // this.
-  context.pattern_block_stack().Push();
   return true;
 }
 
diff --git a/toolchain/check/handle_class.cpp b/toolchain/check/handle_class.cpp
index 36f0664cad700..1c0e55cb62d71 100644
--- a/toolchain/check/handle_class.cpp
+++ b/toolchain/check/handle_class.cpp
@@ -42,10 +42,6 @@ auto HandleParseNode(Context& context, Parse::ClassIntroducerId node_id)
   context.decl_name_stack().PushScopeAndStartName();
   // This class is potentially generic.
   StartGenericDecl(context);
-  // Push a pattern block for the signature (if any) of the first NameComponent.
-  // TODO: Instead use a separate parse node kind for an identifier that's
-  // followed by a pattern, and push a pattern block when handling it.
-  context.pattern_block_stack().Push();
   return true;
 }
 
diff --git a/toolchain/check/handle_export.cpp b/toolchain/check/handle_export.cpp
index ed532f3e1923b..e0b6d19cfe0ad 100644
--- a/toolchain/check/handle_export.cpp
+++ b/toolchain/check/handle_export.cpp
@@ -18,9 +18,6 @@ auto HandleParseNode(Context& context, Parse::ExportIntroducerId /*node_id*/)
   context.decl_introducer_state_stack().Push<Lex::TokenKind::Export>();
   // TODO: Probably need to update DeclNameStack to restrict to only namespaces.
   context.decl_name_stack().PushScopeAndStartName();
-  // The parser supports patterns after `export`, so we need a pattern block
-  // to handle them.
-  context.pattern_block_stack().Push();
   return true;
 }
 
diff --git a/toolchain/check/handle_function.cpp b/toolchain/check/handle_function.cpp
index 694455859dbbb..e9be13ddfdad2 100644
--- a/toolchain/check/handle_function.cpp
+++ b/toolchain/check/handle_function.cpp
@@ -36,8 +36,6 @@ auto HandleParseNode(Context& context, Parse::FunctionIntroducerId node_id)
   context.decl_name_stack().PushScopeAndStartName();
   // The function is potentially generic.
   StartGenericDecl(context);
-  // Start a new pattern block for the signature.
-  context.pattern_block_stack().Push();
   return true;
 }
 
diff --git a/toolchain/check/handle_interface.cpp b/toolchain/check/handle_interface.cpp
index 71967aed041e1..176faf78110ee 100644
--- a/toolchain/check/handle_interface.cpp
+++ b/toolchain/check/handle_interface.cpp
@@ -25,10 +25,6 @@ auto HandleParseNode(Context& context, Parse::InterfaceIntroducerId node_id)
   context.decl_name_stack().PushScopeAndStartName();
   // This interface is potentially generic.
   StartGenericDecl(context);
-  // Push a pattern block for the signature (if any) of the first NameComponent.
-  // TODO: Instead use a separate parse node kind for an identifier that's
-  // followed by a pattern, and push a pattern block when handling it.
-  context.pattern_block_stack().Push();
   return true;
 }
 
diff --git a/toolchain/check/handle_name.cpp b/toolchain/check/handle_name.cpp
index 81880fe14df69..2e117f8d38d3b 100644
--- a/toolchain/check/handle_name.cpp
+++ b/toolchain/check/handle_name.cpp
@@ -123,7 +123,8 @@ static auto HandleNameAsExpr(Context& context, Parse::NodeId node_id,
       {.type_id = type_id, .name_id = name_id, .value_id = result.inst_id});
 }
 
-auto HandleParseNode(Context& context, Parse::IdentifierNameId node_id)
+static auto HandleIdentifierName(Context& context,
+                                 Parse::AnyNonExprIdentifierNameId node_id)
     -> bool {
   // The parent is responsible for binding the name.
   auto name_id = GetIdentifierAsName(context, node_id);
@@ -133,6 +134,18 @@ auto HandleParseNode(Context& context, Parse::IdentifierNameId node_id)
   return true;
 }
 
+auto HandleParseNode(Context& context,
+                     Parse::IdentifierNameNotBeforeParamsId node_id) -> bool {
+  return HandleIdentifierName(context, node_id);
+}
+
+auto HandleParseNode(Context& context,
+                     Parse::IdentifierNameBeforeParamsId node_id) -> bool {
+  // Push a pattern block stack entry to handle the parameter pattern.
+  context.pattern_block_stack().Push();
+  return HandleIdentifierName(context, node_id);
+}
+
 auto HandleParseNode(Context& context, Parse::IdentifierNameExprId node_id)
     -> bool {
   auto name_id = GetIdentifierAsName(context, node_id);
@@ -172,13 +185,15 @@ auto HandleParseNode(Context& context, Parse::SelfValueNameExprId node_id)
   return true;
 }
 
-auto HandleParseNode(Context& context, Parse::NameQualifierId /*node_id*/)
-    -> bool {
+auto HandleParseNode(Context& context,
+                     Parse::NameQualifierWithParamsId /*node_id*/) -> bool {
+  context.decl_name_stack().ApplyNameQualifier(PopNameComponent(context));
+  return true;
+}
+
+auto HandleParseNode(Context& context,
+                     Parse::NameQualifierWithoutParamsId /*node_id*/) -> bool {
   context.decl_name_stack().ApplyNameQualifier(PopNameComponent(context));
-  // Push a pattern block for the signature (if any) of the next NameComponent.
-  // TODO: Instead use a separate parse node kind for an identifier that's
-  // followed by a pattern, and push a pattern block when handling it.
-  context.pattern_block_stack().Push();
   return true;
 }
 
diff --git a/toolchain/check/handle_namespace.cpp b/toolchain/check/handle_namespace.cpp
index bb0be005a0c7d..aa9e28c6a43e6 100644
--- a/toolchain/check/handle_namespace.cpp
+++ b/toolchain/check/handle_namespace.cpp
@@ -19,11 +19,6 @@ auto HandleParseNode(Context& context, Parse::NamespaceStartId /*node_id*/)
   // Optional modifiers and the name follow.
   context.decl_introducer_state_stack().Push<Lex::TokenKind::Namespace>();
   context.decl_name_stack().PushScopeAndStartName();
-
-  // Push a pattern block to handle parameters of the namespace declaration.
-  // TODO: Disallow these in parse, instead of check, so we don't have to do
-  // this.
-  context.pattern_block_stack().Push();
   return true;
 }
 
diff --git a/toolchain/check/inst_block_stack.h b/toolchain/check/inst_block_stack.h
index 6e047bb7c6d77..2558e67bf626f 100644
--- a/toolchain/check/inst_block_stack.h
+++ b/toolchain/check/inst_block_stack.h
@@ -54,7 +54,7 @@ class InstBlockStack {
 
   // Adds the given instruction ID to the block at the top of the stack.
   auto AddInstId(SemIR::InstId inst_id) -> void {
-    CARBON_CHECK(!empty(), "no current block");
+    CARBON_CHECK(!empty(), "{0} has no current block", name_);
     insts_stack_.AppendToTop(inst_id);
   }
 
@@ -74,7 +74,7 @@ class InstBlockStack {
 
   // Runs verification that the processing cleanly finished.
   auto VerifyOnFinish() const -> void {
-    CARBON_CHECK(empty(), "{0}", id_stack_.size());
+    CARBON_CHECK(empty(), "{0} still has {1} entries", name_, id_stack_.size());
   }
 
   auto empty() const -> bool { return id_stack_.empty(); }
diff --git a/toolchain/check/name_component.cpp b/toolchain/check/name_component.cpp
index cc1e6451a697e..fe7e2ffee1b86 100644
--- a/toolchain/check/name_component.cpp
+++ b/toolchain/check/name_component.cpp
@@ -43,11 +43,19 @@ auto PopNameComponent(Context& context, SemIR::InstId return_slot_pattern_id)
     implicit_param_patterns_id = SemIR::InstBlockId::Invalid;
   }
 
-  auto call_params_id =
-      CalleePatternMatch(context, *implicit_param_patterns_id,
-                         *param_patterns_id, return_slot_pattern_id);
+  auto call_params_id = SemIR::InstBlockId::Invalid;
+  auto pattern_block_id = SemIR::InstBlockId::Invalid;
+  if (param_patterns_id->is_valid() || implicit_param_patterns_id->is_valid()) {
+    call_params_id =
+        CalleePatternMatch(context, *implicit_param_patterns_id,
+                           *param_patterns_id, return_slot_pattern_id);
+    pattern_block_id = context.pattern_block_stack().Pop();
+  }
+
+  auto [name_loc_id, name_id] =
+      context.node_stack()
+          .PopWithNodeId<Parse::NodeCategory::NonExprIdentifierName>();
 
-  auto [name_loc_id, name_id] = context.node_stack().PopNameWithNodeId();
   return {
       .name_loc_id = name_loc_id,
       .name_id = name_id,
@@ -59,7 +67,7 @@ auto PopNameComponent(Context& context, SemIR::InstId return_slot_pattern_id)
       .param_patterns_id = *param_patterns_id,
       .call_params_id = call_params_id,
       .return_slot_pattern_id = return_slot_pattern_id,
-      .pattern_block_id = context.pattern_block_stack().Pop(),
+      .pattern_block_id = pattern_block_id,
   };
 }
 
diff --git a/toolchain/check/name_component.h b/toolchain/check/name_component.h
index 8df2263bb5bb6..9dcb79eeb34ed 100644
--- a/toolchain/check/name_component.h
+++ b/toolchain/check/name_component.h
@@ -49,13 +49,14 @@ struct NameComponent {
   SemIR::InstBlockId pattern_block_id;
 };
 
-// Pop a name component from the node stack and pattern block stack.
+// Pops a name component from the node stack (and pattern block stack, if it has
+// parameters).
 auto PopNameComponent(Context& context, SemIR::InstId return_slot_pattern_id =
                                             SemIR::InstId::Invalid)
     -> NameComponent;
 
-// Pop the name of a declaration from the node stack and pattern block stack,
-// and diagnose if it has parameters.
+// Equivalent to PopNameComponent, but also diagnoses if the name component has
+// parameters.
 auto PopNameComponentWithoutParams(Context& context, Lex::TokenKind introducer)
     -> NameComponent;
 
diff --git a/toolchain/check/node_stack.h b/toolchain/check/node_stack.h
index 0de0e75b0aa53..27df2a163c34f 100644
--- a/toolchain/check/node_stack.h
+++ b/toolchain/check/node_stack.h
@@ -386,7 +386,8 @@ class NodeStack {
     // `TuplePattern` produces an `InstBlockId`.
     set_id_if_category_is(Parse::NodeCategory::Expr,
                           Id::KindFor<SemIR::InstId>());
-    set_id_if_category_is(Parse::NodeCategory::MemberName,
+    set_id_if_category_is(Parse::NodeCategory::MemberName |
+                              Parse::NodeCategory::NonExprIdentifierName,
                           Id::KindFor<SemIR::NameId>());
     set_id_if_category_is(Parse::NodeCategory::ImplAs,
                           Id::KindFor<SemIR::InstId>());
@@ -521,7 +522,8 @@ class NodeStack {
         case Parse::NodeKind::ForStatement:
         case Parse::NodeKind::FunctionDecl:
         case Parse::NodeKind::FunctionDefinition:
-        case Parse::NodeKind::IdentifierName:
+        case Parse::NodeKind::IdentifierNameNotBeforeParams:
+        case Parse::NodeKind::IdentifierNameBeforeParams:
         case Parse::NodeKind::IdentifierNameExpr:
         case Parse::NodeKind::IfConditionStart:
         case Parse::NodeKind::IfExprElse:
@@ -594,7 +596,8 @@ class NodeStack {
         case Parse::NodeKind::NamedConstraintDefinition:
         case Parse::NodeKind::NamedConstraintDefinitionStart:
         case Parse::NodeKind::NamedConstraintIntroducer:
-        case Parse::NodeKind::NameQualifier:
+        case Parse::NodeKind::NameQualifierWithParams:
+        case Parse::NodeKind::NameQualifierWithoutParams:
         case Parse::NodeKind::Namespace:
         case Parse::NodeKind::NamespaceStart:
         case Parse::NodeKind::PackageDecl:
diff --git a/toolchain/language_server/handle_document_symbol.cpp b/toolchain/language_server/handle_document_symbol.cpp
index dc86cd8389817..b9b9ff9ac1b14 100644
--- a/toolchain/language_server/handle_document_symbol.cpp
+++ b/toolchain/language_server/handle_document_symbol.cpp
@@ -13,19 +13,25 @@
 
 namespace Carbon::LanguageServer {
 
-// Returns the text of first child of kind Parse::NodeKind::IdentifierName.
+// Returns the text of first child of kind IdentifierNameBeforeParams or
+// IdentifierNameNotBeforeParams.
 static auto GetIdentifierName(const SharedValueStores& value_stores,
                               const Lex::TokenizedBuffer& tokens,
                               const Parse::TreeAndSubtrees& tree_and_subtrees,
                               Parse::NodeId node)
     -> std::optional<llvm::StringRef> {
   for (auto child : tree_and_subtrees.children(node)) {
-    if (tree_and_subtrees.tree().node_kind(child) ==
-        Parse::NodeKind::IdentifierName) {
-      auto token = tree_and_subtrees.tree().node_token(child);
-      if (tokens.GetKind(token) == Lex::TokenKind::Identifier) {
-        return value_stores.identifiers().Get(tokens.GetIdentifier(token));
+    switch (tree_and_subtrees.tree().node_kind(child)) {
+      case Parse::NodeKind::IdentifierNameBeforeParams:
+      case Parse::NodeKind::IdentifierNameNotBeforeParams: {
+        auto token = tree_and_subtrees.tree().node_token(child);
+        if (tokens.GetKind(token) == Lex::TokenKind::Identifier) {
+          return value_stores.identifiers().Get(tokens.GetIdentifier(token));
+        }
+        break;
       }
+      default:
+        break;
     }
   }
   return std::nullopt;
diff --git a/toolchain/parse/handle_binding_pattern.cpp b/toolchain/parse/handle_binding_pattern.cpp
index 77d08143e8ad7..f874b8cf0b147 100644
--- a/toolchain/parse/handle_binding_pattern.cpp
+++ b/toolchain/parse/handle_binding_pattern.cpp
@@ -40,7 +40,7 @@ auto HandleBindingPattern(Context& context) -> void {
   // The first item should be an identifier or `self`.
   bool has_name = false;
   if (auto identifier = context.ConsumeIf(Lex::TokenKind::Identifier)) {
-    context.AddLeafNode(NodeKind::IdentifierName, *identifier);
+    context.AddLeafNode(NodeKind::IdentifierNameNotBeforeParams, *identifier);
     has_name = true;
   } else if (auto self =
                  context.ConsumeIf(Lex::TokenKind::SelfValueIdentifier)) {
@@ -51,8 +51,8 @@ auto HandleBindingPattern(Context& context) -> void {
   }
   if (!has_name) {
     // Add a placeholder for the name.
-    context.AddLeafNode(NodeKind::IdentifierName, *context.position(),
-                        /*has_error=*/true);
+    context.AddLeafNode(NodeKind::IdentifierNameNotBeforeParams,
+                        *context.position(), /*has_error=*/true);
     on_error(/*expected_name=*/true);
   }
 
diff --git a/toolchain/parse/handle_choice.cpp b/toolchain/parse/handle_choice.cpp
index af011615fa800..8dabdfaee5cb1 100644
--- a/toolchain/parse/handle_choice.cpp
+++ b/toolchain/parse/handle_choice.cpp
@@ -50,8 +50,8 @@ auto HandleChoiceAlternative(Context& context) -> void {
 
   context.PushState(State::ChoiceAlternativeFinish);
 
-  if (!context.ConsumeAndAddLeafNodeIf(Lex::TokenKind::Identifier,
-                                       NodeKind::IdentifierName)) {
+  auto token = context.ConsumeIf(Lex::TokenKind::Identifier);
+  if (!token) {
     if (!state.has_error) {
       CARBON_DIAGNOSTIC(ExpectedChoiceAlternativeName, Error,
                         "expected choice alternative name");
@@ -67,7 +67,10 @@ auto HandleChoiceAlternative(Context& context) -> void {
   }
 
   if (context.PositionIs(Lex::TokenKind::OpenParen)) {
+    context.AddLeafNode(NodeKind::IdentifierNameBeforeParams, *token);
     context.PushState(State::PatternListAsTuple);
+  } else {
+    context.AddLeafNode(NodeKind::IdentifierNameNotBeforeParams, *token);
   }
 }
 
diff --git a/toolchain/parse/handle_decl_name_and_params.cpp b/toolchain/parse/handle_decl_name_and_params.cpp
index 99f68823dd69f..d3c0c5f6676e9 100644
--- a/toolchain/parse/handle_decl_name_and_params.cpp
+++ b/toolchain/parse/handle_decl_name_and_params.cpp
@@ -34,29 +34,31 @@ auto HandleDeclNameAndParams(Context& context) -> void {
     return;
   }
 
-  context.AddLeafNode(NodeKind::IdentifierName, *identifier);
-
   switch (context.PositionKind()) {
     case Lex::TokenKind::Period:
-      context.AddNode(NodeKind::NameQualifier,
+      context.AddLeafNode(NodeKind::IdentifierNameNotBeforeParams, *identifier);
+      context.AddNode(NodeKind::NameQualifierWithoutParams,
                       context.ConsumeChecked(Lex::TokenKind::Period),
                       state.has_error);
       context.PushState(State::DeclNameAndParams);
       break;
 
     case Lex::TokenKind::OpenSquareBracket:
+      context.AddLeafNode(NodeKind::IdentifierNameBeforeParams, *identifier);
       state.state = State::DeclNameAndParamsAfterImplicit;
       context.PushState(state);
       context.PushState(State::PatternListAsImplicit);
       break;
 
     case Lex::TokenKind::OpenParen:
+      context.AddLeafNode(NodeKind::IdentifierNameBeforeParams, *identifier);
       state.state = State::DeclNameAndParamsAfterParams;
       context.PushState(state);
       context.PushState(State::PatternListAsTuple);
       break;
 
     default:
+      context.AddLeafNode(NodeKind::IdentifierNameNotBeforeParams, *identifier);
       break;
   }
 }
@@ -82,7 +84,8 @@ auto HandleDeclNameAndParamsAfterParams(Context& context) -> void {
   auto state = context.PopState();
 
   if (auto period = context.ConsumeIf(Lex::TokenKind::Period)) {
-    context.AddNode(NodeKind::NameQualifier, *period, state.has_error);
+    context.AddNode(NodeKind::NameQualifierWithParams, *period,
+                    state.has_error);
     context.PushState(State::DeclNameAndParams);
   }
 }
diff --git a/toolchain/parse/handle_expr.cpp b/toolchain/parse/handle_expr.cpp
index 739ce8df6d52a..558162d95c5e0 100644
--- a/toolchain/parse/handle_expr.cpp
+++ b/toolchain/parse/handle_expr.cpp
@@ -179,8 +179,9 @@ auto HandleExprInPostfix(Context& context) -> void {
       // For periods, we look at the next token to form a designator like
       // `.Member` or `.Self`.
       auto period = context.Consume();
-      if (context.ConsumeAndAddLeafNodeIf(Lex::TokenKind::Identifier,
-                                          NodeKind::IdentifierName)) {
+      if (context.ConsumeAndAddLeafNodeIf(
+              Lex::TokenKind::Identifier,
+              NodeKind::IdentifierNameNotBeforeParams)) {
         // OK, `.` identifier.
       } else if (context.ConsumeAndAddLeafNodeIf(
                      Lex::TokenKind::SelfTypeIdentifier,
@@ -193,8 +194,8 @@ auto HandleExprInPostfix(Context& context) -> void {
                                ExpectedIdentifierOrSelfAfterPeriod);
         // Only consume if it is a number or word.
         if (context.PositionKind().is_keyword()) {
-          context.AddLeafNode(NodeKind::IdentifierName, context.Consume(),
-                              /*has_error=*/true);
+          context.AddLeafNode(NodeKind::IdentifierNameNotBeforeParams,
+                              context.Consume(), /*has_error=*/true);
         } else if (context.PositionIs(Lex::TokenKind::IntLiteral)) {
           context.AddInvalidParse(context.Consume());
         } else {
diff --git a/toolchain/parse/handle_period.cpp b/toolchain/parse/handle_period.cpp
index b29f5b82b7437..8a2f86aa44dee 100644
--- a/toolchain/parse/handle_period.cpp
+++ b/toolchain/parse/handle_period.cpp
@@ -19,8 +19,9 @@ static auto HandlePeriodOrArrow(Context& context, NodeKind node_kind,
   auto dot = context.ConsumeChecked(is_arrow ? Lex::TokenKind::MinusGreater
                                              : Lex::TokenKind::Period);
 
-  if (context.ConsumeAndAddLeafNodeIf(Lex::TokenKind::Identifier,
-                                      NodeKind::IdentifierName)) {
+  if (context.ConsumeAndAddLeafNodeIf(
+          Lex::TokenKind::Identifier,
+          NodeKind::IdentifierNameNotBeforeParams)) {
     // OK, `.` identifier.
   } else if (context.ConsumeAndAddLeafNodeIf(Lex::TokenKind::Base,
                                              NodeKind::BaseName)) {
@@ -43,11 +44,11 @@ static auto HandlePeriodOrArrow(Context& context, NodeKind node_kind,
     // If we see a keyword, assume it was intended to be a name.
     // TODO: Should keywords be valid here?
     if (context.PositionKind().is_keyword()) {
-      context.AddLeafNode(NodeKind::IdentifierName, context.Consume(),
-                          /*has_error=*/true);
+      context.AddLeafNode(NodeKind::IdentifierNameNotBeforeParams,
+                          context.Consume(), /*has_error=*/true);
     } else {
-      context.AddLeafNode(NodeKind::IdentifierName, *context.position(),
-                          /*has_error=*/true);
+      context.AddLeafNode(NodeKind::IdentifierNameNotBeforeParams,
+                          *context.position(), /*has_error=*/true);
       // Indicate the error to the parent state so that it can avoid producing
       // more errors.
       context.ReturnErrorOnState();
diff --git a/toolchain/parse/handle_requirement.cpp b/toolchain/parse/handle_requirement.cpp
index e5345ff573394..1586389d87109 100644
--- a/toolchain/parse/handle_requirement.cpp
+++ b/toolchain/parse/handle_requirement.cpp
@@ -18,7 +18,7 @@ auto HandleRequirementBegin(Context& context) -> void {
       context.PositionKind(static_cast<Lookahead>(2)) ==
           Lex::TokenKind::Equal) {
     auto period = context.Consume();
-    context.AddNode(NodeKind::IdentifierName, context.Consume(),
+    context.AddNode(NodeKind::IdentifierNameNotBeforeParams, context.Consume(),
                     /*has_error=*/false);
     context.AddNode(NodeKind::DesignatorExpr, period, /*has_error=*/false);
     state.token = context.Consume();
diff --git a/toolchain/parse/node_ids.h b/toolchain/parse/node_ids.h
index cba0c4693be74..117cd1fbab163 100644
--- a/toolchain/parse/node_ids.h
+++ b/toolchain/parse/node_ids.h
@@ -81,6 +81,8 @@ using AnyPatternId = NodeIdInCategory<NodeCategory::Pattern>;
 using AnyStatementId =
     NodeIdInCategory<NodeCategory::Statement | NodeCategory::Decl>;
 using AnyRequirementId = NodeIdInCategory<NodeCategory::Requirement>;
+using AnyNonExprIdentifierNameId =
+    NodeIdInCategory<NodeCategory::NonExprIdentifierName>;
 
 // NodeId with kind that matches one of the `T::Kind`s.
 template <typename... T>
diff --git a/toolchain/parse/node_kind.def b/toolchain/parse/node_kind.def
index dafb04ed25220..cd0886f31f126 100644
--- a/toolchain/parse/node_kind.def
+++ b/toolchain/parse/node_kind.def
@@ -94,7 +94,8 @@ CARBON_PARSE_NODE_KIND(Placeholder)
 
 CARBON_PARSE_NODE_KIND(EmptyDecl)
 
-CARBON_PARSE_NODE_KIND(IdentifierName)
+CARBON_PARSE_NODE_KIND(IdentifierNameNotBeforeParams)
+CARBON_PARSE_NODE_KIND(IdentifierNameBeforeParams)
 
 CARBON_PARSE_NODE_KIND(IdentifierNameExpr)
 
@@ -119,7 +120,8 @@ CARBON_PARSE_NODE_KIND(LibraryDecl)
 
 CARBON_PARSE_NODE_KIND(LibrarySpecifier)
 
-CARBON_PARSE_NODE_KIND(NameQualifier)
+CARBON_PARSE_NODE_KIND(NameQualifierWithParams)
+CARBON_PARSE_NODE_KIND(NameQualifierWithoutParams)
 
 CARBON_PARSE_NODE_KIND(ExportIntroducer)
 CARBON_PARSE_NODE_KIND(ExportDecl)
diff --git a/toolchain/parse/node_kind.h b/toolchain/parse/node_kind.h
index 8dccf7e9c5d35..ef36537ce6feb 100644
--- a/toolchain/parse/node_kind.h
+++ b/toolchain/parse/node_kind.h
@@ -35,9 +35,10 @@ class NodeCategory : public Printable<NodeCategory> {
     Statement = 1 << 7,
     IntConst = 1 << 8,
     Requirement = 1 << 9,
+    NonExprIdentifierName = 1 << 10,
     None = 0,
 
-    LLVM_MARK_AS_BITMASK_ENUM(/*LargestValue=*/Requirement)
+    LLVM_MARK_AS_BITMASK_ENUM(/*LargestValue=*/NonExprIdentifierName)
   };
 
   // Support implicit conversion so that the difference with the member enum is
diff --git a/toolchain/parse/testdata/alias/basic.carbon b/toolchain/parse/testdata/alias/basic.carbon
index d74c1db4e8a76..6bfed47039c29 100644
--- a/toolchain/parse/testdata/alias/basic.carbon
+++ b/toolchain/parse/testdata/alias/basic.carbon
@@ -26,45 +26,45 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'AliasIntroducer', text: 'alias'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:       {kind: 'AliasInitializer', text: '='},
 // CHECK:STDOUT:       {kind: 'IdentifierNameExpr', text: 'foo'},
 // CHECK:STDOUT:     {kind: 'Alias', text: ';', subtree_size: 5},
 // CHECK:STDOUT:       {kind: 'AliasIntroducer', text: 'alias'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:       {kind: 'AliasInitializer', text: '='},
 // CHECK:STDOUT:       {kind: 'IntLiteral', text: '0'},
 // CHECK:STDOUT:     {kind: 'Alias', text: ';', subtree_size: 5},
 // CHECK:STDOUT:       {kind: 'AliasIntroducer', text: 'alias'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'c'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'c'},
 // CHECK:STDOUT:       {kind: 'AliasInitializer', text: '='},
 // CHECK:STDOUT:         {kind: 'IntLiteral', text: '1'},
 // CHECK:STDOUT:         {kind: 'IntLiteral', text: '3'},
 // CHECK:STDOUT:       {kind: 'InfixOperatorPlus', text: '+', subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'Alias', text: ';', subtree_size: 7},
 // CHECK:STDOUT:       {kind: 'AliasIntroducer', text: 'alias'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'NS'},
-// CHECK:STDOUT:       {kind: 'NameQualifier', text: '.', subtree_size: 2},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'ns'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'NS'},
+// CHECK:STDOUT:       {kind: 'NameQualifierWithoutParams', text: '.', subtree_size: 2},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'ns'},
 // CHECK:STDOUT:       {kind: 'AliasInitializer', text: '='},
 // CHECK:STDOUT:       {kind: 'IdentifierNameExpr', text: 'foo'},
 // CHECK:STDOUT:     {kind: 'Alias', text: ';', subtree_size: 7},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'C'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'C'},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'AliasIntroducer', text: 'alias'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'c'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'c'},
 // CHECK:STDOUT:         {kind: 'AliasInitializer', text: '='},
 // CHECK:STDOUT:         {kind: 'IdentifierNameExpr', text: 'foo'},
 // CHECK:STDOUT:       {kind: 'Alias', text: ';', subtree_size: 5},
 // CHECK:STDOUT:     {kind: 'ClassDefinition', text: '}', subtree_size: 9},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'AliasIntroducer', text: 'alias'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'f'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'f'},
 // CHECK:STDOUT:         {kind: 'AliasInitializer', text: '='},
 // CHECK:STDOUT:         {kind: 'IdentifierNameExpr', text: 'foo'},
 // CHECK:STDOUT:       {kind: 'Alias', text: ';', subtree_size: 5},
diff --git a/toolchain/parse/testdata/alias/fail_syntax.carbon b/toolchain/parse/testdata/alias/fail_syntax.carbon
index 0cdb27c9c204d..b00c42757c2be 100644
--- a/toolchain/parse/testdata/alias/fail_syntax.carbon
+++ b/toolchain/parse/testdata/alias/fail_syntax.carbon
@@ -82,29 +82,29 @@ alias a = b
 // CHECK:STDOUT:       {kind: 'InvalidParse', text: '=', has_error: yes},
 // CHECK:STDOUT:     {kind: 'Alias', text: ';', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'AliasIntroducer', text: 'alias'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:     {kind: 'Alias', text: ';', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'AliasIntroducer', text: 'alias'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:       {kind: 'AliasInitializer', text: '='},
 // CHECK:STDOUT:       {kind: 'InvalidParse', text: ';', has_error: yes},
 // CHECK:STDOUT:     {kind: 'Alias', text: ';', has_error: yes, subtree_size: 5},
 // CHECK:STDOUT:       {kind: 'AliasIntroducer', text: 'alias'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:     {kind: 'Alias', text: ';', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'AliasIntroducer', text: 'alias'},
 // CHECK:STDOUT:       {kind: 'InvalidParse', text: '=', has_error: yes},
 // CHECK:STDOUT:     {kind: 'Alias', text: ';', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'AliasIntroducer', text: 'alias'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:     {kind: 'Alias', text: ';', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'AliasIntroducer', text: 'alias'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:       {kind: 'AliasInitializer', text: '='},
 // CHECK:STDOUT:       {kind: 'IdentifierNameExpr', text: 'b'},
 // CHECK:STDOUT:     {kind: 'Alias', text: ';', has_error: yes, subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
@@ -112,18 +112,18 @@ alias a = b
 // CHECK:STDOUT:         {kind: 'InvalidParse', text: ';', has_error: yes},
 // CHECK:STDOUT:       {kind: 'Alias', text: ';', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'AliasIntroducer', text: 'alias'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:         {kind: 'AliasInitializer', text: '='},
 // CHECK:STDOUT:         {kind: 'InvalidParse', text: ';', has_error: yes},
 // CHECK:STDOUT:       {kind: 'Alias', text: ';', has_error: yes, subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'AliasIntroducer', text: 'alias'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:         {kind: 'AliasInitializer', text: '='},
 // CHECK:STDOUT:         {kind: 'InvalidParse', text: '}', has_error: yes},
 // CHECK:STDOUT:       {kind: 'Alias', text: '=', has_error: yes, subtree_size: 5},
 // CHECK:STDOUT:     {kind: 'FunctionDefinition', text: '}', subtree_size: 19},
 // CHECK:STDOUT:       {kind: 'AliasIntroducer', text: 'alias'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:       {kind: 'AliasInitializer', text: '='},
 // CHECK:STDOUT:       {kind: 'IdentifierNameExpr', text: 'b'},
 // CHECK:STDOUT:     {kind: 'Alias', text: 'b', has_error: yes, subtree_size: 5},
diff --git a/toolchain/parse/testdata/array/fail_require_close_bracket.carbon b/toolchain/parse/testdata/array/fail_require_close_bracket.carbon
index dd6b12a5f6209..77584ce69bb7a 100644
--- a/toolchain/parse/testdata/array/fail_require_close_bracket.carbon
+++ b/toolchain/parse/testdata/array/fail_require_close_bracket.carbon
@@ -18,7 +18,7 @@ var x: [i32;;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:         {kind: 'InvalidParse', text: '[', has_error: yes},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'VariableDecl', text: ';', subtree_size: 5},
diff --git a/toolchain/parse/testdata/array/fail_require_semi.carbon b/toolchain/parse/testdata/array/fail_require_semi.carbon
index 804653a7f8a15..a40746f9af744 100644
--- a/toolchain/parse/testdata/array/fail_require_semi.carbon
+++ b/toolchain/parse/testdata/array/fail_require_semi.carbon
@@ -17,7 +17,7 @@ var x: [i32];
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:             {kind: 'ArrayExprStart', text: '['},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'ArrayExprSemi', text: ']', has_error: yes, subtree_size: 3},
diff --git a/toolchain/parse/testdata/array/fail_syntax.carbon b/toolchain/parse/testdata/array/fail_syntax.carbon
index 9b3632700ed20..e3527b08e685a 100644
--- a/toolchain/parse/testdata/array/fail_syntax.carbon
+++ b/toolchain/parse/testdata/array/fail_syntax.carbon
@@ -71,7 +71,7 @@ var x: [i32];
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:             {kind: 'ArrayExprStart', text: '['},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'ArrayExprSemi', text: ']', has_error: yes, subtree_size: 3},
@@ -84,7 +84,7 @@ var x: [i32];
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'X'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'X'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'ArrayExprStart', text: '['},
@@ -100,7 +100,7 @@ var x: [i32];
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'y'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'y'},
 // CHECK:STDOUT:             {kind: 'ArrayExprStart', text: '['},
 // CHECK:STDOUT:             {kind: 'InvalidParse', text: '`', has_error: yes},
 // CHECK:STDOUT:           {kind: 'ArrayExprSemi', text: '`', has_error: yes, subtree_size: 3},
@@ -114,7 +114,7 @@ var x: [i32];
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:         {kind: 'InvalidParse', text: '[', has_error: yes},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'VariableDecl', text: ';', subtree_size: 5},
@@ -125,7 +125,7 @@ var x: [i32];
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:             {kind: 'ArrayExprStart', text: '['},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'ArrayExprSemi', text: ']', has_error: yes, subtree_size: 3},
diff --git a/toolchain/parse/testdata/array/with_length.carbon b/toolchain/parse/testdata/array/with_length.carbon
index 84217ed5ba67e..cca2c1287273c 100644
--- a/toolchain/parse/testdata/array/with_length.carbon
+++ b/toolchain/parse/testdata/array/with_length.carbon
@@ -14,7 +14,7 @@ var x: [i32; 10];
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:             {kind: 'ArrayExprStart', text: '['},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'ArrayExprSemi', text: ';', subtree_size: 3},
diff --git a/toolchain/parse/testdata/array/without_length.carbon b/toolchain/parse/testdata/array/without_length.carbon
index 68d0ba0a027bb..83e9088ac0a64 100644
--- a/toolchain/parse/testdata/array/without_length.carbon
+++ b/toolchain/parse/testdata/array/without_length.carbon
@@ -14,7 +14,7 @@ var x: [i32;];
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:             {kind: 'ArrayExprStart', text: '['},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'ArrayExprSemi', text: ';', subtree_size: 3},
diff --git a/toolchain/parse/testdata/auto/let.carbon b/toolchain/parse/testdata/auto/let.carbon
index 1a71fa826d0e6..45dc504b89727 100644
--- a/toolchain/parse/testdata/auto/let.carbon
+++ b/toolchain/parse/testdata/auto/let.carbon
@@ -14,7 +14,7 @@ let x: auto = 1;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'LetIntroducer', text: 'let'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:         {kind: 'AutoTypeLiteral', text: 'auto'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'LetInitializer', text: '='},
diff --git a/toolchain/parse/testdata/auto/match_case.carbon b/toolchain/parse/testdata/auto/match_case.carbon
index af9345a09937f..db7bafec9f3ac 100644
--- a/toolchain/parse/testdata/auto/match_case.carbon
+++ b/toolchain/parse/testdata/auto/match_case.carbon
@@ -19,7 +19,7 @@ fn f() -> bool {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'f'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'f'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'BoolTypeLiteral', text: 'bool'},
@@ -31,7 +31,7 @@ fn f() -> bool {
 // CHECK:STDOUT:           {kind: 'MatchCondition', text: ')', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'MatchStatementStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:             {kind: 'MatchCaseIntroducer', text: 'case'},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:               {kind: 'AutoTypeLiteral', text: 'auto'},
 // CHECK:STDOUT:             {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:               {kind: 'MatchCaseGuardIntroducer', text: 'if'},
diff --git a/toolchain/parse/testdata/auto/return.carbon b/toolchain/parse/testdata/auto/return.carbon
index 3b520bea5a578..4fc149cf74396 100644
--- a/toolchain/parse/testdata/auto/return.carbon
+++ b/toolchain/parse/testdata/auto/return.carbon
@@ -16,7 +16,7 @@ fn f() -> auto {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'f'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'f'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'AutoTypeLiteral', text: 'auto'},
diff --git a/toolchain/parse/testdata/auto/var.carbon b/toolchain/parse/testdata/auto/var.carbon
index 7c4820fa97833..1f7259a02f949 100644
--- a/toolchain/parse/testdata/auto/var.carbon
+++ b/toolchain/parse/testdata/auto/var.carbon
@@ -14,7 +14,7 @@ var y: auto = false;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'y'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'y'},
 // CHECK:STDOUT:         {kind: 'AutoTypeLiteral', text: 'auto'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/basics/builtin_types.carbon b/toolchain/parse/testdata/basics/builtin_types.carbon
index afbe80ba1e0a9..a76f41f947ba1 100644
--- a/toolchain/parse/testdata/basics/builtin_types.carbon
+++ b/toolchain/parse/testdata/basics/builtin_types.carbon
@@ -16,21 +16,21 @@ var test_str: String = "Test";
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'test_i32'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'test_i32'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
 // CHECK:STDOUT:       {kind: 'IntLiteral', text: '0'},
 // CHECK:STDOUT:     {kind: 'VariableDecl', text: ';', subtree_size: 7},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'test_f64'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'test_f64'},
 // CHECK:STDOUT:         {kind: 'FloatTypeLiteral', text: 'f64'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
 // CHECK:STDOUT:       {kind: 'RealLiteral', text: '0.1'},
 // CHECK:STDOUT:     {kind: 'VariableDecl', text: ';', subtree_size: 7},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'test_str'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'test_str'},
 // CHECK:STDOUT:         {kind: 'StringTypeLiteral', text: 'String'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/basics/fail_bracket_recovery.carbon b/toolchain/parse/testdata/basics/fail_bracket_recovery.carbon
index 11c86138fda7f..af36800e46685 100644
--- a/toolchain/parse/testdata/basics/fail_bracket_recovery.carbon
+++ b/toolchain/parse/testdata/basics/fail_bracket_recovery.carbon
@@ -33,12 +33,12 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:             {kind: 'ParenExprStart', text: '('},
 // CHECK:STDOUT:                 {kind: 'ArrayExprStart', text: '['},
 // CHECK:STDOUT:                 {kind: 'IntTypeLiteral', text: 'i32'},
@@ -57,9 +57,9 @@ fn F() {
 // CHECK:STDOUT:         {kind: 'TupleLiteral', text: ')', subtree_size: 7},
 // CHECK:STDOUT:       {kind: 'VariableDecl', text: ';', subtree_size: 19},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:             {kind: 'StructTypeLiteralStart', text: '{'},
-// CHECK:STDOUT:                 {kind: 'IdentifierName', text: 'y'},
+// CHECK:STDOUT:                 {kind: 'IdentifierNameNotBeforeParams', text: 'y'},
 // CHECK:STDOUT:               {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:                 {kind: 'TupleLiteralStart', text: '('},
 // CHECK:STDOUT:               {kind: 'TupleLiteral', text: ')', subtree_size: 2},
@@ -68,7 +68,7 @@ fn F() {
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 9},
 // CHECK:STDOUT:         {kind: 'VariableInitializer', text: '='},
 // CHECK:STDOUT:           {kind: 'StructLiteralStart', text: '{'},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'y'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'y'},
 // CHECK:STDOUT:             {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:               {kind: 'ParenExprStart', text: '('},
 // CHECK:STDOUT:                 {kind: 'TupleLiteralStart', text: '('},
diff --git a/toolchain/parse/testdata/basics/fail_invalid_designators.carbon b/toolchain/parse/testdata/basics/fail_invalid_designators.carbon
index b018b3fd208f3..29ab7997f05ef 100644
--- a/toolchain/parse/testdata/basics/fail_invalid_designators.carbon
+++ b/toolchain/parse/testdata/basics/fail_invalid_designators.carbon
@@ -25,16 +25,16 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:           {kind: 'IdentifierNameExpr', text: 'a'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: ';', has_error: yes},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: ';', has_error: yes},
 // CHECK:STDOUT:         {kind: 'MemberAccessExpr', text: '.', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ExprStatement', text: ';', has_error: yes, subtree_size: 4},
 // CHECK:STDOUT:           {kind: 'IdentifierNameExpr', text: 'a'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'fn', has_error: yes},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'fn', has_error: yes},
 // CHECK:STDOUT:         {kind: 'MemberAccessExpr', text: '.', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ExprStatement', text: ';', subtree_size: 4},
 // CHECK:STDOUT:     {kind: 'FunctionDefinition', text: '}', subtree_size: 14},
diff --git a/toolchain/parse/testdata/basics/fail_paren_match_regression.carbon b/toolchain/parse/testdata/basics/fail_paren_match_regression.carbon
index d87ae18a1503b..0003b7339bc82 100644
--- a/toolchain/parse/testdata/basics/fail_paren_match_regression.carbon
+++ b/toolchain/parse/testdata/basics/fail_paren_match_regression.carbon
@@ -25,7 +25,7 @@ var = (foo {})
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: '=', has_error: yes},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: '=', has_error: yes},
 // CHECK:STDOUT:         {kind: 'InvalidParse', text: '=', has_error: yes},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: '=', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/basics/function_call.carbon b/toolchain/parse/testdata/basics/function_call.carbon
index c6b8753460550..6188a0f3f24a3 100644
--- a/toolchain/parse/testdata/basics/function_call.carbon
+++ b/toolchain/parse/testdata/basics/function_call.carbon
@@ -17,25 +17,25 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:                       {kind: 'IdentifierNameExpr', text: 'a'},
-// CHECK:STDOUT:                       {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:                       {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:                     {kind: 'MemberAccessExpr', text: '.', subtree_size: 3},
-// CHECK:STDOUT:                     {kind: 'IdentifierName', text: 'f'},
+// CHECK:STDOUT:                     {kind: 'IdentifierNameNotBeforeParams', text: 'f'},
 // CHECK:STDOUT:                   {kind: 'MemberAccessExpr', text: '.', subtree_size: 5},
 // CHECK:STDOUT:                 {kind: 'CallExprStart', text: '(', subtree_size: 6},
 // CHECK:STDOUT:                   {kind: 'IdentifierNameExpr', text: 'c'},
-// CHECK:STDOUT:                   {kind: 'IdentifierName', text: 'd'},
+// CHECK:STDOUT:                   {kind: 'IdentifierNameNotBeforeParams', text: 'd'},
 // CHECK:STDOUT:                 {kind: 'MemberAccessExpr', text: '.', subtree_size: 3},
 // CHECK:STDOUT:                 {kind: 'CallExprComma', text: ','},
 // CHECK:STDOUT:                   {kind: 'ParenExprStart', text: '('},
 // CHECK:STDOUT:                   {kind: 'IdentifierNameExpr', text: 'e'},
 // CHECK:STDOUT:                 {kind: 'ParenExpr', text: ')', subtree_size: 3},
 // CHECK:STDOUT:               {kind: 'CallExpr', text: ')', subtree_size: 14},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'g'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'g'},
 // CHECK:STDOUT:             {kind: 'MemberAccessExpr', text: '.', subtree_size: 16},
 // CHECK:STDOUT:           {kind: 'CallExprStart', text: '(', subtree_size: 17},
 // CHECK:STDOUT:         {kind: 'CallExpr', text: ')', subtree_size: 18},
diff --git a/toolchain/parse/testdata/basics/multifile.carbon b/toolchain/parse/testdata/basics/multifile.carbon
index afe3328df11c1..f515e0312aa80 100644
--- a/toolchain/parse/testdata/basics/multifile.carbon
+++ b/toolchain/parse/testdata/basics/multifile.carbon
@@ -18,7 +18,7 @@ fn B() {}
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'A'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'A'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
@@ -29,7 +29,7 @@ fn B() {}
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'B'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'B'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/basics/numeric_literals.carbon b/toolchain/parse/testdata/basics/numeric_literals.carbon
index 63b92b669512d..5c214168b1367 100644
--- a/toolchain/parse/testdata/basics/numeric_literals.carbon
+++ b/toolchain/parse/testdata/basics/numeric_literals.carbon
@@ -33,12 +33,12 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'ints'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'ints'},
 // CHECK:STDOUT:               {kind: 'ArrayExprStart', text: '['},
 // CHECK:STDOUT:               {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:             {kind: 'ArrayExprSemi', text: ';', subtree_size: 3},
@@ -60,7 +60,7 @@ fn F() {
 // CHECK:STDOUT:         {kind: 'TupleLiteral', text: ')', subtree_size: 12},
 // CHECK:STDOUT:       {kind: 'VariableDecl', text: ';', subtree_size: 22},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'floats'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'floats'},
 // CHECK:STDOUT:               {kind: 'ArrayExprStart', text: '['},
 // CHECK:STDOUT:               {kind: 'FloatTypeLiteral', text: 'f64'},
 // CHECK:STDOUT:             {kind: 'ArrayExprSemi', text: ';', subtree_size: 3},
diff --git a/toolchain/parse/testdata/basics/parens.carbon b/toolchain/parse/testdata/basics/parens.carbon
index ad0a0c2b37b1a..85712afb2b110 100644
--- a/toolchain/parse/testdata/basics/parens.carbon
+++ b/toolchain/parse/testdata/basics/parens.carbon
@@ -16,9 +16,9 @@ fn F(n: i32) -> i32 {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 5},
diff --git a/toolchain/parse/testdata/choice/basic.carbon b/toolchain/parse/testdata/choice/basic.carbon
index 74057417651e4..33d289de9ee38 100644
--- a/toolchain/parse/testdata/choice/basic.carbon
+++ b/toolchain/parse/testdata/choice/basic.carbon
@@ -19,15 +19,15 @@ choice Ordering {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'ChoiceIntroducer', text: 'choice'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Ordering'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'Ordering'},
 // CHECK:STDOUT:       {kind: 'ChoiceDefinitionStart', text: '{', subtree_size: 3},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Less'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'Less'},
 // CHECK:STDOUT:       {kind: 'ChoiceAlternativeListComma', text: ','},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Equivalent'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'Equivalent'},
 // CHECK:STDOUT:       {kind: 'ChoiceAlternativeListComma', text: ','},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Greater'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'Greater'},
 // CHECK:STDOUT:       {kind: 'ChoiceAlternativeListComma', text: ','},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Incomparable'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'Incomparable'},
 // CHECK:STDOUT:     {kind: 'ChoiceDefinition', text: '}', subtree_size: 11},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
 // CHECK:STDOUT:   ]
diff --git a/toolchain/parse/testdata/choice/fail_alternative_with_implicit_params.carbon b/toolchain/parse/testdata/choice/fail_alternative_with_implicit_params.carbon
index 19bc2b9855df2..0f42830d1be5e 100644
--- a/toolchain/parse/testdata/choice/fail_alternative_with_implicit_params.carbon
+++ b/toolchain/parse/testdata/choice/fail_alternative_with_implicit_params.carbon
@@ -19,9 +19,9 @@ choice X {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'ChoiceIntroducer', text: 'choice'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'X'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'X'},
 // CHECK:STDOUT:       {kind: 'ChoiceDefinitionStart', text: '{', subtree_size: 3},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'A'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'A'},
 // CHECK:STDOUT:     {kind: 'ChoiceDefinition', text: '}', has_error: yes, subtree_size: 5},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
 // CHECK:STDOUT:   ]
diff --git a/toolchain/parse/testdata/choice/fail_invalid_alternative_identifier.carbon b/toolchain/parse/testdata/choice/fail_invalid_alternative_identifier.carbon
index b5db9f3a5f06f..77e8d5b656bf7 100644
--- a/toolchain/parse/testdata/choice/fail_invalid_alternative_identifier.carbon
+++ b/toolchain/parse/testdata/choice/fail_invalid_alternative_identifier.carbon
@@ -25,9 +25,9 @@ choice InvalidAlternativeIdentifier {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'ChoiceIntroducer', text: 'choice'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'InvalidAlternativeIdentifier'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'InvalidAlternativeIdentifier'},
 // CHECK:STDOUT:       {kind: 'ChoiceDefinitionStart', text: '{', subtree_size: 3},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Other'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'Other'},
 // CHECK:STDOUT:     {kind: 'ChoiceDefinition', text: '}', has_error: yes, subtree_size: 5},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
 // CHECK:STDOUT:   ]
diff --git a/toolchain/parse/testdata/choice/fail_invalid_braces.carbon b/toolchain/parse/testdata/choice/fail_invalid_braces.carbon
index 762769b836124..d1180d1f86b9e 100644
--- a/toolchain/parse/testdata/choice/fail_invalid_braces.carbon
+++ b/toolchain/parse/testdata/choice/fail_invalid_braces.carbon
@@ -23,7 +23,7 @@ choice InvalidBraces |
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'ChoiceIntroducer', text: 'choice'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'InvalidBraces'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'InvalidBraces'},
 // CHECK:STDOUT:       {kind: 'ChoiceDefinitionStart', text: '|', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'ChoiceDefinition', text: '|', has_error: yes, subtree_size: 4},
 // CHECK:STDOUT:       {kind: 'InvalidParseStart', text: '|', has_error: yes},
diff --git a/toolchain/parse/testdata/choice/fail_missing_definition.carbon b/toolchain/parse/testdata/choice/fail_missing_definition.carbon
index fc6d7e8b08ac4..2d23da8fabd9e 100644
--- a/toolchain/parse/testdata/choice/fail_missing_definition.carbon
+++ b/toolchain/parse/testdata/choice/fail_missing_definition.carbon
@@ -17,7 +17,7 @@ choice MissingDefinition;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'ChoiceIntroducer', text: 'choice'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'MissingDefinition'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'MissingDefinition'},
 // CHECK:STDOUT:       {kind: 'ChoiceDefinitionStart', text: ';', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'ChoiceDefinition', text: ';', has_error: yes, subtree_size: 4},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
diff --git a/toolchain/parse/testdata/choice/fail_missing_definition_parameterized.carbon b/toolchain/parse/testdata/choice/fail_missing_definition_parameterized.carbon
index 8a76d9af0768c..3f01488589047 100644
--- a/toolchain/parse/testdata/choice/fail_missing_definition_parameterized.carbon
+++ b/toolchain/parse/testdata/choice/fail_missing_definition_parameterized.carbon
@@ -17,9 +17,9 @@ choice MissingDefinition(T:! type);
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'ChoiceIntroducer', text: 'choice'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'MissingDefinition'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'MissingDefinition'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'T'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'T'},
 // CHECK:STDOUT:             {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:           {kind: 'CompileTimeBindingPattern', text: ':!', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 5},
diff --git a/toolchain/parse/testdata/choice/fail_qualified_alternative_name.carbon b/toolchain/parse/testdata/choice/fail_qualified_alternative_name.carbon
index 76402ce451f10..c3f3fc08ac693 100644
--- a/toolchain/parse/testdata/choice/fail_qualified_alternative_name.carbon
+++ b/toolchain/parse/testdata/choice/fail_qualified_alternative_name.carbon
@@ -19,9 +19,9 @@ choice X {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'ChoiceIntroducer', text: 'choice'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'X'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'X'},
 // CHECK:STDOUT:       {kind: 'ChoiceDefinitionStart', text: '{', subtree_size: 3},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'A'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'A'},
 // CHECK:STDOUT:     {kind: 'ChoiceDefinition', text: '}', has_error: yes, subtree_size: 5},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
 // CHECK:STDOUT:   ]
diff --git a/toolchain/parse/testdata/choice/local.carbon b/toolchain/parse/testdata/choice/local.carbon
index 0e0d9f499960a..13f473a77d62f 100644
--- a/toolchain/parse/testdata/choice/local.carbon
+++ b/toolchain/parse/testdata/choice/local.carbon
@@ -19,16 +19,16 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:           {kind: 'ChoiceIntroducer', text: 'choice'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'C'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'C'},
 // CHECK:STDOUT:         {kind: 'ChoiceDefinitionStart', text: '{', subtree_size: 3},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'X'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'X'},
 // CHECK:STDOUT:         {kind: 'ChoiceAlternativeListComma', text: ','},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Y'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'Y'},
 // CHECK:STDOUT:       {kind: 'ChoiceDefinition', text: '}', subtree_size: 7},
 // CHECK:STDOUT:     {kind: 'FunctionDefinition', text: '}', subtree_size: 13},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
diff --git a/toolchain/parse/testdata/choice/modifiers.carbon b/toolchain/parse/testdata/choice/modifiers.carbon
index e365cb4d8536f..90dadc1181167 100644
--- a/toolchain/parse/testdata/choice/modifiers.carbon
+++ b/toolchain/parse/testdata/choice/modifiers.carbon
@@ -20,15 +20,15 @@ private choice Ordering {
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'ChoiceIntroducer', text: 'choice'},
 // CHECK:STDOUT:         {kind: 'PrivateModifier', text: 'private'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Ordering'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'Ordering'},
 // CHECK:STDOUT:       {kind: 'ChoiceDefinitionStart', text: '{', subtree_size: 4},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Less'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'Less'},
 // CHECK:STDOUT:       {kind: 'ChoiceAlternativeListComma', text: ','},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Equivalent'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'Equivalent'},
 // CHECK:STDOUT:       {kind: 'ChoiceAlternativeListComma', text: ','},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Greater'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'Greater'},
 // CHECK:STDOUT:       {kind: 'ChoiceAlternativeListComma', text: ','},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Incomparable'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'Incomparable'},
 // CHECK:STDOUT:     {kind: 'ChoiceDefinition', text: '}', subtree_size: 12},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
 // CHECK:STDOUT:   ]
diff --git a/toolchain/parse/testdata/choice/parameterized.carbon b/toolchain/parse/testdata/choice/parameterized.carbon
index 34d5ef2935be7..5002961ec3bd3 100644
--- a/toolchain/parse/testdata/choice/parameterized.carbon
+++ b/toolchain/parse/testdata/choice/parameterized.carbon
@@ -17,21 +17,21 @@ choice OptionalElement(T:! type) {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'ChoiceIntroducer', text: 'choice'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'OptionalElement'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'OptionalElement'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'T'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'T'},
 // CHECK:STDOUT:             {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:           {kind: 'CompileTimeBindingPattern', text: ':!', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 5},
 // CHECK:STDOUT:       {kind: 'ChoiceDefinitionStart', text: '{', subtree_size: 8},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Element'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'Element'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'value'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'value'},
 // CHECK:STDOUT:           {kind: 'IdentifierNameExpr', text: 'T'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 5},
 // CHECK:STDOUT:       {kind: 'ChoiceAlternativeListComma', text: ','},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'None'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'None'},
 // CHECK:STDOUT:       {kind: 'ChoiceAlternativeListComma', text: ','},
 // CHECK:STDOUT:     {kind: 'ChoiceDefinition', text: '}', subtree_size: 18},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
diff --git a/toolchain/parse/testdata/class/adapt.carbon b/toolchain/parse/testdata/class/adapt.carbon
index f75df418337d8..2d3b64f613015 100644
--- a/toolchain/parse/testdata/class/adapt.carbon
+++ b/toolchain/parse/testdata/class/adapt.carbon
@@ -74,7 +74,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'A'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'A'},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'AdaptIntroducer', text: 'adapt'},
 // CHECK:STDOUT:           {kind: 'TupleLiteralStart', text: '('},
@@ -82,31 +82,31 @@ fn F() {
 // CHECK:STDOUT:       {kind: 'AdaptDecl', text: ';', subtree_size: 4},
 // CHECK:STDOUT:     {kind: 'ClassDefinition', text: '}', subtree_size: 8},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'B'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'B'},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'AdaptIntroducer', text: 'adapt'},
 // CHECK:STDOUT:         {kind: 'IdentifierNameExpr', text: 'A'},
 // CHECK:STDOUT:       {kind: 'AdaptDecl', text: ';', subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'ClassDefinition', text: '}', subtree_size: 7},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'C'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'C'},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'AdaptIntroducer', text: 'adapt'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:       {kind: 'AdaptDecl', text: ';', subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'ClassDefinition', text: '}', subtree_size: 7},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'D'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'D'},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'AdaptIntroducer', text: 'adapt'},
 // CHECK:STDOUT:         {kind: 'ExtendModifier', text: 'extend'},
 // CHECK:STDOUT:           {kind: 'StructTypeLiteralStart', text: '{'},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:             {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'StructTypeLiteralField', text: ':', subtree_size: 4},
 // CHECK:STDOUT:           {kind: 'StructTypeLiteralComma', text: ','},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:             {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'StructTypeLiteralField', text: ':', subtree_size: 4},
@@ -114,7 +114,7 @@ fn F() {
 // CHECK:STDOUT:       {kind: 'AdaptDecl', text: ';', subtree_size: 14},
 // CHECK:STDOUT:     {kind: 'ClassDefinition', text: '}', subtree_size: 18},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'E'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'E'},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'AdaptIntroducer', text: 'adapt'},
 // CHECK:STDOUT:             {kind: 'IdentifierNameExpr', text: 'GetType'},
@@ -132,35 +132,35 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'A'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'A'},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'AdaptIntroducer', text: 'adapt'},
 // CHECK:STDOUT:         {kind: 'IntLiteral', text: '1'},
 // CHECK:STDOUT:       {kind: 'AdaptDecl', text: ';', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'ClassDefinition', text: '}', subtree_size: 7},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'B'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'B'},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'AdaptIntroducer', text: 'adapt'},
 // CHECK:STDOUT:         {kind: 'InvalidParse', text: ';', has_error: yes},
 // CHECK:STDOUT:       {kind: 'AdaptDecl', text: ';', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'ClassDefinition', text: '}', subtree_size: 7},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'C'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'C'},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'AdaptIntroducer', text: 'adapt'},
 // CHECK:STDOUT:         {kind: 'InvalidParse', text: '}', has_error: yes},
 // CHECK:STDOUT:       {kind: 'AdaptDecl', text: 'adapt', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'ClassDefinition', text: '}', subtree_size: 7},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'D'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'D'},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'AdaptIntroducer', text: 'adapt'},
 // CHECK:STDOUT:         {kind: 'InvalidParse', text: 'class', has_error: yes},
 // CHECK:STDOUT:       {kind: 'AdaptDecl', text: ';', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'ClassDefinition', text: '}', subtree_size: 7},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/class/base.carbon b/toolchain/parse/testdata/class/base.carbon
index 459bcde326f08..beb5ecd7908af 100644
--- a/toolchain/parse/testdata/class/base.carbon
+++ b/toolchain/parse/testdata/class/base.carbon
@@ -22,11 +22,11 @@ class D {
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
 // CHECK:STDOUT:         {kind: 'BaseModifier', text: 'base'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'B'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'B'},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 4},
 // CHECK:STDOUT:     {kind: 'ClassDefinition', text: '}', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'D'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'D'},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'BaseIntroducer', text: 'base'},
 // CHECK:STDOUT:         {kind: 'BaseColon', text: ':'},
@@ -39,12 +39,12 @@ class D {
 // CHECK:STDOUT:       {kind: 'BaseDecl', text: ';', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
 // CHECK:STDOUT:         {kind: 'BaseModifier', text: 'base'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Nested'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'Nested'},
 // CHECK:STDOUT:       {kind: 'ClassDecl', text: ';', subtree_size: 4},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
 // CHECK:STDOUT:         {kind: 'PrivateModifier', text: 'private'},
 // CHECK:STDOUT:         {kind: 'BaseModifier', text: 'base'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'PrivateNested'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'PrivateNested'},
 // CHECK:STDOUT:       {kind: 'ClassDecl', text: ';', subtree_size: 5},
 // CHECK:STDOUT:     {kind: 'ClassDefinition', text: '}', subtree_size: 22},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
diff --git a/toolchain/parse/testdata/class/base_misplaced.carbon b/toolchain/parse/testdata/class/base_misplaced.carbon
index f8e495ebe14d1..0e35b94fd2922 100644
--- a/toolchain/parse/testdata/class/base_misplaced.carbon
+++ b/toolchain/parse/testdata/class/base_misplaced.carbon
@@ -23,7 +23,7 @@ fn F() {
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
 // CHECK:STDOUT:         {kind: 'BaseModifier', text: 'base'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'B'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'B'},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 4},
 // CHECK:STDOUT:     {kind: 'ClassDefinition', text: '}', subtree_size: 5},
 // CHECK:STDOUT:       {kind: 'BaseIntroducer', text: 'base'},
@@ -31,7 +31,7 @@ fn F() {
 // CHECK:STDOUT:       {kind: 'IdentifierNameExpr', text: 'B'},
 // CHECK:STDOUT:     {kind: 'BaseDecl', text: ';', subtree_size: 4},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/class/basic.carbon b/toolchain/parse/testdata/class/basic.carbon
index a344a2dd0ed43..81e6711e3fa82 100644
--- a/toolchain/parse/testdata/class/basic.carbon
+++ b/toolchain/parse/testdata/class/basic.carbon
@@ -16,10 +16,10 @@ class Foo {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Baz'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'Baz'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDecl', text: ';', subtree_size: 5},
diff --git a/toolchain/parse/testdata/class/fail_base.carbon b/toolchain/parse/testdata/class/fail_base.carbon
index 19ff6ed1d2223..97d4ae62208b2 100644
--- a/toolchain/parse/testdata/class/fail_base.carbon
+++ b/toolchain/parse/testdata/class/fail_base.carbon
@@ -37,7 +37,7 @@ class A {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'A'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'A'},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'BaseIntroducer', text: 'base'},
 // CHECK:STDOUT:       {kind: 'BaseDecl', text: ';', has_error: yes, subtree_size: 2},
diff --git a/toolchain/parse/testdata/class/fail_modifiers.carbon b/toolchain/parse/testdata/class/fail_modifiers.carbon
index 3d8ed25cbb145..d636e9d7e1d15 100644
--- a/toolchain/parse/testdata/class/fail_modifiers.carbon
+++ b/toolchain/parse/testdata/class/fail_modifiers.carbon
@@ -38,7 +38,7 @@ class C {
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'ClassIntroducer', text: 'class'},
 // CHECK:STDOUT:       {kind: 'VirtualModifier', text: 'virtual'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'B'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'B'},
 // CHECK:STDOUT:     {kind: 'ClassDecl', text: 'B', has_error: yes, subtree_size: 4},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
 // CHECK:STDOUT:   ]
@@ -55,7 +55,7 @@ class C {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'C'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'C'},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'AdaptIntroducer', text: 'adapt'},
 // CHECK:STDOUT:         {kind: 'ExtendModifier', text: 'extend'},
diff --git a/toolchain/parse/testdata/class/fn_definitions.carbon b/toolchain/parse/testdata/class/fn_definitions.carbon
index 6c6bd02efff2f..b943f27bac04a 100644
--- a/toolchain/parse/testdata/class/fn_definitions.carbon
+++ b/toolchain/parse/testdata/class/fn_definitions.carbon
@@ -20,10 +20,10 @@ class Foo {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'Make'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameBeforeParams', text: 'Make'},
 // CHECK:STDOUT:             {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:           {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'SelfTypeNameExpr', text: 'Self'},
@@ -31,7 +31,7 @@ class Foo {
 // CHECK:STDOUT:         {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 7},
 // CHECK:STDOUT:           {kind: 'ReturnStatementStart', text: 'return'},
 // CHECK:STDOUT:             {kind: 'StructLiteralStart', text: '{'},
-// CHECK:STDOUT:                 {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:                 {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:               {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:               {kind: 'IntLiteral', text: '0'},
 // CHECK:STDOUT:             {kind: 'StructLiteralField', text: '=', subtree_size: 4},
@@ -39,7 +39,7 @@ class Foo {
 // CHECK:STDOUT:         {kind: 'ReturnStatement', text: ';', subtree_size: 8},
 // CHECK:STDOUT:       {kind: 'FunctionDefinition', text: '}', subtree_size: 16},
 // CHECK:STDOUT:           {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'Baz'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameBeforeParams', text: 'Baz'},
 // CHECK:STDOUT:             {kind: 'ImplicitParamListStart', text: '['},
 // CHECK:STDOUT:               {kind: 'SelfValueName', text: 'self'},
 // CHECK:STDOUT:               {kind: 'SelfTypeNameExpr', text: 'Self'},
@@ -52,12 +52,12 @@ class Foo {
 // CHECK:STDOUT:         {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 12},
 // CHECK:STDOUT:           {kind: 'ReturnStatementStart', text: 'return'},
 // CHECK:STDOUT:             {kind: 'SelfValueNameExpr', text: 'self'},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:           {kind: 'MemberAccessExpr', text: '.', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'ReturnStatement', text: ';', subtree_size: 5},
 // CHECK:STDOUT:       {kind: 'FunctionDefinition', text: '}', subtree_size: 18},
 // CHECK:STDOUT:           {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'Modify'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameBeforeParams', text: 'Modify'},
 // CHECK:STDOUT:             {kind: 'ImplicitParamListStart', text: '['},
 // CHECK:STDOUT:                 {kind: 'SelfValueName', text: 'self'},
 // CHECK:STDOUT:                   {kind: 'SelfTypeNameExpr', text: 'Self'},
@@ -69,7 +69,7 @@ class Foo {
 // CHECK:STDOUT:           {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:         {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 12},
 // CHECK:STDOUT:               {kind: 'SelfValueNameExpr', text: 'self'},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:             {kind: 'PointerMemberAccessExpr', text: '->', subtree_size: 3},
 // CHECK:STDOUT:             {kind: 'IntLiteral', text: '1'},
 // CHECK:STDOUT:           {kind: 'InfixOperatorEqual', text: '=', subtree_size: 5},
diff --git a/toolchain/parse/testdata/class/introducer.carbon b/toolchain/parse/testdata/class/introducer.carbon
index 60fac4891aef3..bcebaf418cc0a 100644
--- a/toolchain/parse/testdata/class/introducer.carbon
+++ b/toolchain/parse/testdata/class/introducer.carbon
@@ -22,37 +22,37 @@ extern class D {}
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'A'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'A'},
 // CHECK:STDOUT:     {kind: 'ClassDecl', text: ';', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ClassIntroducer', text: 'class'},
 // CHECK:STDOUT:       {kind: 'BaseModifier', text: 'base'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'B'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'B'},
 // CHECK:STDOUT:     {kind: 'ClassDecl', text: ';', subtree_size: 4},
 // CHECK:STDOUT:       {kind: 'ClassIntroducer', text: 'class'},
 // CHECK:STDOUT:       {kind: 'AbstractModifier', text: 'abstract'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'C'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'C'},
 // CHECK:STDOUT:     {kind: 'ClassDecl', text: ';', subtree_size: 4},
 // CHECK:STDOUT:       {kind: 'ClassIntroducer', text: 'class'},
 // CHECK:STDOUT:       {kind: 'ExternModifier', text: 'extern'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'D'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'D'},
 // CHECK:STDOUT:     {kind: 'ClassDecl', text: ';', subtree_size: 4},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'A'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'A'},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'ClassDefinition', text: '}', subtree_size: 4},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
 // CHECK:STDOUT:         {kind: 'BaseModifier', text: 'base'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'B'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'B'},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 4},
 // CHECK:STDOUT:     {kind: 'ClassDefinition', text: '}', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
 // CHECK:STDOUT:         {kind: 'AbstractModifier', text: 'abstract'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'C'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'C'},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 4},
 // CHECK:STDOUT:     {kind: 'ClassDefinition', text: '}', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
 // CHECK:STDOUT:         {kind: 'ExternModifier', text: 'extern'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'D'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'D'},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 4},
 // CHECK:STDOUT:     {kind: 'ClassDefinition', text: '}', subtree_size: 5},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
diff --git a/toolchain/parse/testdata/class/local.carbon b/toolchain/parse/testdata/class/local.carbon
index 128e8049687f8..f72499cb5fef5 100644
--- a/toolchain/parse/testdata/class/local.carbon
+++ b/toolchain/parse/testdata/class/local.carbon
@@ -20,29 +20,29 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:           {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'C'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'C'},
 // CHECK:STDOUT:         {kind: 'ClassDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:             {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'G'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameBeforeParams', text: 'G'},
 // CHECK:STDOUT:               {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:             {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'FunctionDefinition', text: '}', subtree_size: 6},
 // CHECK:STDOUT:           {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'H'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameBeforeParams', text: 'H'},
 // CHECK:STDOUT:             {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:           {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:         {kind: 'FunctionDecl', text: ';', subtree_size: 5},
 // CHECK:STDOUT:       {kind: 'ClassDefinition', text: '}', subtree_size: 15},
 // CHECK:STDOUT:           {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'C'},
-// CHECK:STDOUT:           {kind: 'NameQualifier', text: '.', subtree_size: 2},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'H'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'C'},
+// CHECK:STDOUT:           {kind: 'NameQualifierWithoutParams', text: '.', subtree_size: 2},
+// CHECK:STDOUT:           {kind: 'IdentifierNameBeforeParams', text: 'H'},
 // CHECK:STDOUT:             {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:           {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:         {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 7},
diff --git a/toolchain/parse/testdata/class/mismatched_introducer.carbon b/toolchain/parse/testdata/class/mismatched_introducer.carbon
index 620053f0b7f0f..90cc2847be146 100644
--- a/toolchain/parse/testdata/class/mismatched_introducer.carbon
+++ b/toolchain/parse/testdata/class/mismatched_introducer.carbon
@@ -18,18 +18,18 @@ abstract base class C;
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'InterfaceIntroducer', text: 'interface'},
 // CHECK:STDOUT:       {kind: 'AbstractModifier', text: 'abstract'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'I'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'I'},
 // CHECK:STDOUT:     {kind: 'InterfaceDecl', text: ';', subtree_size: 4},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
 // CHECK:STDOUT:       {kind: 'BaseModifier', text: 'base'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ';', subtree_size: 6},
 // CHECK:STDOUT:       {kind: 'ClassIntroducer', text: 'class'},
 // CHECK:STDOUT:       {kind: 'AbstractModifier', text: 'abstract'},
 // CHECK:STDOUT:       {kind: 'BaseModifier', text: 'base'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'C'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'C'},
 // CHECK:STDOUT:     {kind: 'ClassDecl', text: ';', subtree_size: 5},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
 // CHECK:STDOUT:   ]
diff --git a/toolchain/parse/testdata/class/var.carbon b/toolchain/parse/testdata/class/var.carbon
index d93cff0f43e57..a2bc404248f42 100644
--- a/toolchain/parse/testdata/class/var.carbon
+++ b/toolchain/parse/testdata/class/var.carbon
@@ -16,10 +16,10 @@ class Foo {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableDecl', text: ';', subtree_size: 5},
diff --git a/toolchain/parse/testdata/for/fail_colon_instead_of_in.carbon b/toolchain/parse/testdata/for/fail_colon_instead_of_in.carbon
index 1041c4cc442dd..42291f69d96f8 100644
--- a/toolchain/parse/testdata/for/fail_colon_instead_of_in.carbon
+++ b/toolchain/parse/testdata/for/fail_colon_instead_of_in.carbon
@@ -21,13 +21,13 @@ fn foo() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'foo'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'foo'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:           {kind: 'ForHeaderStart', text: '('},
 // CHECK:STDOUT:             {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:               {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:             {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'ForIn', text: ':', has_error: yes, subtree_size: 5},
diff --git a/toolchain/parse/testdata/for/fail_missing_cond.carbon b/toolchain/parse/testdata/for/fail_missing_cond.carbon
index e24eab8a1cd63..9fb55398e01c6 100644
--- a/toolchain/parse/testdata/for/fail_missing_cond.carbon
+++ b/toolchain/parse/testdata/for/fail_missing_cond.carbon
@@ -32,7 +32,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/for/fail_missing_in.carbon b/toolchain/parse/testdata/for/fail_missing_in.carbon
index 40073c480d1d2..30c848a9e0e2a 100644
--- a/toolchain/parse/testdata/for/fail_missing_in.carbon
+++ b/toolchain/parse/testdata/for/fail_missing_in.carbon
@@ -21,13 +21,13 @@ fn foo() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'foo'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'foo'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:           {kind: 'ForHeaderStart', text: '('},
 // CHECK:STDOUT:             {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:               {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:             {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'ForIn', text: 'var', has_error: yes, subtree_size: 5},
diff --git a/toolchain/parse/testdata/for/fail_missing_var.carbon b/toolchain/parse/testdata/for/fail_missing_var.carbon
index ed5317ca21f4e..cbe47c6f3d9fe 100644
--- a/toolchain/parse/testdata/for/fail_missing_var.carbon
+++ b/toolchain/parse/testdata/for/fail_missing_var.carbon
@@ -21,7 +21,7 @@ fn foo() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'foo'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'foo'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/for/fail_returned_var.carbon b/toolchain/parse/testdata/for/fail_returned_var.carbon
index 9867023c392ac..f7da37a5b825b 100644
--- a/toolchain/parse/testdata/for/fail_returned_var.carbon
+++ b/toolchain/parse/testdata/for/fail_returned_var.carbon
@@ -22,7 +22,7 @@ fn foo() -> i32 {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'foo'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'foo'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
diff --git a/toolchain/parse/testdata/for/fail_square_brackets.carbon b/toolchain/parse/testdata/for/fail_square_brackets.carbon
index 3be3f2e73c751..df4447e571752 100644
--- a/toolchain/parse/testdata/for/fail_square_brackets.carbon
+++ b/toolchain/parse/testdata/for/fail_square_brackets.carbon
@@ -32,7 +32,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/for/nested.carbon b/toolchain/parse/testdata/for/nested.carbon
index d7ed13452212a..deb6d30bd4a93 100644
--- a/toolchain/parse/testdata/for/nested.carbon
+++ b/toolchain/parse/testdata/for/nested.carbon
@@ -20,13 +20,13 @@ fn foo() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'foo'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'foo'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:           {kind: 'ForHeaderStart', text: '('},
 // CHECK:STDOUT:             {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'y'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'y'},
 // CHECK:STDOUT:               {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:             {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'ForIn', text: 'in', subtree_size: 5},
@@ -35,7 +35,7 @@ fn foo() {
 // CHECK:STDOUT:           {kind: 'CodeBlockStart', text: '{'},
 // CHECK:STDOUT:               {kind: 'ForHeaderStart', text: '('},
 // CHECK:STDOUT:                 {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:                   {kind: 'IdentifierName', text: 'z'},
+// CHECK:STDOUT:                   {kind: 'IdentifierNameNotBeforeParams', text: 'z'},
 // CHECK:STDOUT:                   {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:                 {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:               {kind: 'ForIn', text: 'in', subtree_size: 5},
diff --git a/toolchain/parse/testdata/for/simple.carbon b/toolchain/parse/testdata/for/simple.carbon
index 48f63c17eb004..b9e827c864a78 100644
--- a/toolchain/parse/testdata/for/simple.carbon
+++ b/toolchain/parse/testdata/for/simple.carbon
@@ -18,13 +18,13 @@ fn foo() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'foo'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'foo'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:           {kind: 'ForHeaderStart', text: '('},
 // CHECK:STDOUT:             {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:               {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:             {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'ForIn', text: 'in', subtree_size: 5},
diff --git a/toolchain/parse/testdata/function/declaration/addr.carbon b/toolchain/parse/testdata/function/declaration/addr.carbon
index ae55ee1967be2..f110028693f3e 100644
--- a/toolchain/parse/testdata/function/declaration/addr.carbon
+++ b/toolchain/parse/testdata/function/declaration/addr.carbon
@@ -14,9 +14,9 @@ fn foo(addr a: i32*);
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'foo'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:               {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:             {kind: 'PostfixOperatorStar', text: '*', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 4},
diff --git a/toolchain/parse/testdata/function/declaration/basic.carbon b/toolchain/parse/testdata/function/declaration/basic.carbon
index 42aaefbd458a5..c9367f43dfa44 100644
--- a/toolchain/parse/testdata/function/declaration/basic.carbon
+++ b/toolchain/parse/testdata/function/declaration/basic.carbon
@@ -14,7 +14,7 @@ fn F();
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ';', subtree_size: 5},
diff --git a/toolchain/parse/testdata/function/declaration/extern.carbon b/toolchain/parse/testdata/function/declaration/extern.carbon
index f9a46bc3d4f9a..af6f6d8a276f1 100644
--- a/toolchain/parse/testdata/function/declaration/extern.carbon
+++ b/toolchain/parse/testdata/function/declaration/extern.carbon
@@ -44,7 +44,7 @@ extern library foo fn G();
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
 // CHECK:STDOUT:       {kind: 'ExternModifier', text: 'extern'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'G'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'G'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ';', subtree_size: 6},
@@ -57,7 +57,7 @@ extern library foo fn G();
 // CHECK:STDOUT:           {kind: 'LibraryName', text: '"foo"'},
 // CHECK:STDOUT:         {kind: 'LibrarySpecifier', text: 'library', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'ExternModifierWithLibrary', text: 'extern', subtree_size: 3},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'G'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'G'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ';', subtree_size: 8},
@@ -70,7 +70,7 @@ extern library foo fn G();
 // CHECK:STDOUT:           {kind: 'DefaultLibrary', text: 'default'},
 // CHECK:STDOUT:         {kind: 'LibrarySpecifier', text: 'library', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'ExternModifierWithLibrary', text: 'extern', subtree_size: 3},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'G'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'G'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ';', subtree_size: 8},
@@ -83,7 +83,7 @@ extern library foo fn G();
 // CHECK:STDOUT:           {kind: 'LibraryName', text: 'fn', has_error: yes},
 // CHECK:STDOUT:         {kind: 'LibrarySpecifier', text: 'library', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'ExternModifierWithLibrary', text: 'extern', subtree_size: 3},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'G'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'G'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ';', subtree_size: 8},
diff --git a/toolchain/parse/testdata/function/declaration/fail_identifier_instead_of_sig.carbon b/toolchain/parse/testdata/function/declaration/fail_identifier_instead_of_sig.carbon
index 648904850d4d0..4e22b2268bb28 100644
--- a/toolchain/parse/testdata/function/declaration/fail_identifier_instead_of_sig.carbon
+++ b/toolchain/parse/testdata/function/declaration/fail_identifier_instead_of_sig.carbon
@@ -17,7 +17,7 @@ fn foo bar;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'foo'},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ';', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
 // CHECK:STDOUT:   ]
diff --git a/toolchain/parse/testdata/function/declaration/fail_missing_implicit_close.carbon b/toolchain/parse/testdata/function/declaration/fail_missing_implicit_close.carbon
index 5515742c60bd8..be0d9dba90856 100644
--- a/toolchain/parse/testdata/function/declaration/fail_missing_implicit_close.carbon
+++ b/toolchain/parse/testdata/function/declaration/fail_missing_implicit_close.carbon
@@ -22,7 +22,7 @@ fn Div[();
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Div'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'Div'},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ';', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
 // CHECK:STDOUT:   ]
diff --git a/toolchain/parse/testdata/function/declaration/fail_no_sig_or_semi.carbon b/toolchain/parse/testdata/function/declaration/fail_no_sig_or_semi.carbon
index 4fa758ee17163..63a9e0ee54256 100644
--- a/toolchain/parse/testdata/function/declaration/fail_no_sig_or_semi.carbon
+++ b/toolchain/parse/testdata/function/declaration/fail_no_sig_or_semi.carbon
@@ -17,7 +17,7 @@ fn foo
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'foo'},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: 'fn', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
 // CHECK:STDOUT:   ]
diff --git a/toolchain/parse/testdata/function/declaration/fail_skip_indented_newline_until_outdent.carbon b/toolchain/parse/testdata/function/declaration/fail_skip_indented_newline_until_outdent.carbon
index 3822b48b6bb54..a7e84e1baba42 100644
--- a/toolchain/parse/testdata/function/declaration/fail_skip_indented_newline_until_outdent.carbon
+++ b/toolchain/parse/testdata/function/declaration/fail_skip_indented_newline_until_outdent.carbon
@@ -23,7 +23,7 @@ fn F();
 // CHECK:STDOUT:       {kind: 'InvalidParse', text: '(', has_error: yes},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ')', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ';', subtree_size: 5},
diff --git a/toolchain/parse/testdata/function/declaration/fail_skip_indented_newline_with_semi.carbon b/toolchain/parse/testdata/function/declaration/fail_skip_indented_newline_with_semi.carbon
index 4cef41901e227..a49ecc8b4af7a 100644
--- a/toolchain/parse/testdata/function/declaration/fail_skip_indented_newline_with_semi.carbon
+++ b/toolchain/parse/testdata/function/declaration/fail_skip_indented_newline_with_semi.carbon
@@ -23,7 +23,7 @@ fn F();
 // CHECK:STDOUT:       {kind: 'InvalidParse', text: '(', has_error: yes},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ';', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ';', subtree_size: 5},
diff --git a/toolchain/parse/testdata/function/declaration/fail_skip_indented_newline_without_semi.carbon b/toolchain/parse/testdata/function/declaration/fail_skip_indented_newline_without_semi.carbon
index b3516fc84ec36..367cc3fe5fc92 100644
--- a/toolchain/parse/testdata/function/declaration/fail_skip_indented_newline_without_semi.carbon
+++ b/toolchain/parse/testdata/function/declaration/fail_skip_indented_newline_without_semi.carbon
@@ -23,7 +23,7 @@ fn F();
 // CHECK:STDOUT:       {kind: 'InvalidParse', text: '(', has_error: yes},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ')', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ';', subtree_size: 5},
diff --git a/toolchain/parse/testdata/function/declaration/fail_skip_to_newline_without_semi.carbon b/toolchain/parse/testdata/function/declaration/fail_skip_to_newline_without_semi.carbon
index d7d24fcc919ed..569f33ba28fc2 100644
--- a/toolchain/parse/testdata/function/declaration/fail_skip_to_newline_without_semi.carbon
+++ b/toolchain/parse/testdata/function/declaration/fail_skip_to_newline_without_semi.carbon
@@ -21,7 +21,7 @@ fn F();
 // CHECK:STDOUT:       {kind: 'InvalidParse', text: '(', has_error: yes},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ')', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ';', subtree_size: 5},
diff --git a/toolchain/parse/testdata/function/declaration/fail_skip_without_semi_to_curly.carbon b/toolchain/parse/testdata/function/declaration/fail_skip_without_semi_to_curly.carbon
index 05f07584cb71f..d63d38f1ff1dc 100644
--- a/toolchain/parse/testdata/function/declaration/fail_skip_without_semi_to_curly.carbon
+++ b/toolchain/parse/testdata/function/declaration/fail_skip_without_semi_to_curly.carbon
@@ -20,7 +20,7 @@ fn F();
 // CHECK:STDOUT:       {kind: 'InvalidParseStart', text: 'struct', has_error: yes},
 // CHECK:STDOUT:     {kind: 'InvalidParseSubtree', text: '}', has_error: yes, subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ';', subtree_size: 5},
diff --git a/toolchain/parse/testdata/function/declaration/fail_with_identifier_as_param.carbon b/toolchain/parse/testdata/function/declaration/fail_with_identifier_as_param.carbon
index cfc7e2d8a6c56..029da10ad2456 100644
--- a/toolchain/parse/testdata/function/declaration/fail_with_identifier_as_param.carbon
+++ b/toolchain/parse/testdata/function/declaration/fail_with_identifier_as_param.carbon
@@ -17,9 +17,9 @@ fn foo(bar);
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'foo'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'bar'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'bar'},
 // CHECK:STDOUT:           {kind: 'InvalidParse', text: ')', has_error: yes},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: 'bar', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', has_error: yes, subtree_size: 5},
diff --git a/toolchain/parse/testdata/function/declaration/impl_fn.carbon b/toolchain/parse/testdata/function/declaration/impl_fn.carbon
index dd40b80186395..0a0e7b66f8da3 100644
--- a/toolchain/parse/testdata/function/declaration/impl_fn.carbon
+++ b/toolchain/parse/testdata/function/declaration/impl_fn.carbon
@@ -18,21 +18,21 @@ private impl default fn I();
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
 // CHECK:STDOUT:       {kind: 'ImplModifier', text: 'impl'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ';', subtree_size: 6},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
 // CHECK:STDOUT:       {kind: 'AbstractModifier', text: 'abstract'},
 // CHECK:STDOUT:       {kind: 'ImplModifier', text: 'impl'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'G'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'G'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ';', subtree_size: 7},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
 // CHECK:STDOUT:       {kind: 'ImplModifier', text: 'impl'},
 // CHECK:STDOUT:       {kind: 'AbstractModifier', text: 'abstract'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'H'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'H'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ';', subtree_size: 7},
@@ -40,7 +40,7 @@ private impl default fn I();
 // CHECK:STDOUT:       {kind: 'PrivateModifier', text: 'private'},
 // CHECK:STDOUT:       {kind: 'ImplModifier', text: 'impl'},
 // CHECK:STDOUT:       {kind: 'DefaultModifier', text: 'default'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'I'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'I'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ';', subtree_size: 8},
diff --git a/toolchain/parse/testdata/function/declaration/implicit_empty.carbon b/toolchain/parse/testdata/function/declaration/implicit_empty.carbon
index c8b4efd3b96f0..21a78462c9710 100644
--- a/toolchain/parse/testdata/function/declaration/implicit_empty.carbon
+++ b/toolchain/parse/testdata/function/declaration/implicit_empty.carbon
@@ -14,7 +14,7 @@ fn foo[]();
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'foo'},
 // CHECK:STDOUT:         {kind: 'ImplicitParamListStart', text: '['},
 // CHECK:STDOUT:       {kind: 'ImplicitParamList', text: ']', subtree_size: 2},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
diff --git a/toolchain/parse/testdata/function/declaration/implicit_params.carbon b/toolchain/parse/testdata/function/declaration/implicit_params.carbon
index 8c1f096e44c72..8c4d1dbd636a3 100644
--- a/toolchain/parse/testdata/function/declaration/implicit_params.carbon
+++ b/toolchain/parse/testdata/function/declaration/implicit_params.carbon
@@ -14,13 +14,13 @@ fn foo[a: i32, b: i32]();
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'foo'},
 // CHECK:STDOUT:         {kind: 'ImplicitParamListStart', text: '['},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ImplicitParamList', text: ']', subtree_size: 9},
diff --git a/toolchain/parse/testdata/function/declaration/no_params.carbon b/toolchain/parse/testdata/function/declaration/no_params.carbon
index 66eb3f8453672..eff50acad90d0 100644
--- a/toolchain/parse/testdata/function/declaration/no_params.carbon
+++ b/toolchain/parse/testdata/function/declaration/no_params.carbon
@@ -14,7 +14,7 @@ fn foo {}
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'foo'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'foo'},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'FunctionDefinition', text: '}', subtree_size: 4},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
diff --git a/toolchain/parse/testdata/function/declaration/params.carbon b/toolchain/parse/testdata/function/declaration/params.carbon
index 5aad2495ec19a..e5cef3886c461 100644
--- a/toolchain/parse/testdata/function/declaration/params.carbon
+++ b/toolchain/parse/testdata/function/declaration/params.carbon
@@ -14,13 +14,13 @@ fn foo(a: i32, b: i32);
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'foo'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 9},
diff --git a/toolchain/parse/testdata/function/declaration/with_return_type.carbon b/toolchain/parse/testdata/function/declaration/with_return_type.carbon
index 82d49a414d9c6..a869793be16ec 100644
--- a/toolchain/parse/testdata/function/declaration/with_return_type.carbon
+++ b/toolchain/parse/testdata/function/declaration/with_return_type.carbon
@@ -14,7 +14,7 @@ fn foo() -> u32;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'foo'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:         {kind: 'UnsignedIntTypeLiteral', text: 'u32'},
diff --git a/toolchain/parse/testdata/function/definition/basic.carbon b/toolchain/parse/testdata/function/definition/basic.carbon
index 135d9643022c9..444357dd4982f 100644
--- a/toolchain/parse/testdata/function/definition/basic.carbon
+++ b/toolchain/parse/testdata/function/definition/basic.carbon
@@ -14,7 +14,7 @@ fn F() {}
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/function/definition/builtin.carbon b/toolchain/parse/testdata/function/definition/builtin.carbon
index e4662a51b7bd4..8c1f889826d61 100644
--- a/toolchain/parse/testdata/function/definition/builtin.carbon
+++ b/toolchain/parse/testdata/function/definition/builtin.carbon
@@ -18,7 +18,7 @@ impl T as I {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'BuiltinFunctionDefinitionStart', text: '=', subtree_size: 5},
@@ -30,7 +30,7 @@ impl T as I {
 // CHECK:STDOUT:         {kind: 'IdentifierNameExpr', text: 'I'},
 // CHECK:STDOUT:       {kind: 'ImplDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:           {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'Op'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameBeforeParams', text: 'Op'},
 // CHECK:STDOUT:             {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:           {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:         {kind: 'BuiltinFunctionDefinitionStart', text: '=', subtree_size: 5},
diff --git a/toolchain/parse/testdata/function/definition/decl_statement.carbon b/toolchain/parse/testdata/function/definition/decl_statement.carbon
index 044fab4b796e8..8d89ebf21f7a0 100644
--- a/toolchain/parse/testdata/function/definition/decl_statement.carbon
+++ b/toolchain/parse/testdata/function/definition/decl_statement.carbon
@@ -46,41 +46,41 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'AliasIntroducer', text: 'alias'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'A'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'A'},
 // CHECK:STDOUT:         {kind: 'AliasInitializer', text: '='},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:       {kind: 'Alias', text: ';', subtree_size: 5},
 // CHECK:STDOUT:           {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'A'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'A'},
 // CHECK:STDOUT:         {kind: 'ClassDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ClassDefinition', text: '}', subtree_size: 4},
 // CHECK:STDOUT:           {kind: 'ClassIntroducer', text: 'class'},
 // CHECK:STDOUT:           {kind: 'BaseModifier', text: 'base'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'B'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'B'},
 // CHECK:STDOUT:         {kind: 'ClassDefinitionStart', text: '{', subtree_size: 4},
 // CHECK:STDOUT:       {kind: 'ClassDefinition', text: '}', subtree_size: 5},
 // CHECK:STDOUT:           {kind: 'ClassIntroducer', text: 'class'},
 // CHECK:STDOUT:           {kind: 'AbstractModifier', text: 'abstract'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'Abstract'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'Abstract'},
 // CHECK:STDOUT:         {kind: 'ClassDefinitionStart', text: '{', subtree_size: 4},
 // CHECK:STDOUT:       {kind: 'ClassDefinition', text: '}', subtree_size: 5},
 // CHECK:STDOUT:           {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:             {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:           {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:         {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:       {kind: 'FunctionDefinition', text: '}', subtree_size: 6},
 // CHECK:STDOUT:           {kind: 'NamedConstraintIntroducer', text: 'constraint'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'C'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'C'},
 // CHECK:STDOUT:         {kind: 'NamedConstraintDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'NamedConstraintDefinition', text: '}', subtree_size: 4},
 // CHECK:STDOUT:           {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'I'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'I'},
 // CHECK:STDOUT:         {kind: 'InterfaceDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'InterfaceDefinition', text: '}', subtree_size: 4},
 // CHECK:STDOUT:           {kind: 'ImplIntroducer', text: 'impl'},
@@ -97,18 +97,18 @@ fn F() {
 // CHECK:STDOUT:         {kind: 'ImplDefinitionStart', text: '{', subtree_size: 6},
 // CHECK:STDOUT:       {kind: 'ImplDefinition', text: '}', subtree_size: 7},
 // CHECK:STDOUT:           {kind: 'ChoiceIntroducer', text: 'choice'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'C'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'C'},
 // CHECK:STDOUT:         {kind: 'ChoiceDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ChoiceDefinition', text: '}', subtree_size: 4},
 // CHECK:STDOUT:         {kind: 'LetIntroducer', text: 'let'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'LetInitializer', text: '='},
 // CHECK:STDOUT:         {kind: 'IntLiteral', text: '0'},
 // CHECK:STDOUT:       {kind: 'LetDecl', text: ';', subtree_size: 7},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'v'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'v'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableDecl', text: ';', subtree_size: 5},
@@ -119,7 +119,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
@@ -141,35 +141,35 @@ fn F() {
 // CHECK:STDOUT:         {kind: 'IdentifierNameExpr', text: 'I'},
 // CHECK:STDOUT:       {kind: 'ImplDecl', text: ';', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'NamespaceStart', text: 'namespace'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'N'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'N'},
 // CHECK:STDOUT:       {kind: 'Namespace', text: ';', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
 // CHECK:STDOUT:         {kind: 'DefaultModifier', text: 'default'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDecl', text: ';', subtree_size: 6},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
 // CHECK:STDOUT:         {kind: 'ImplModifier', text: 'impl'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'G'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'G'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDecl', text: ';', subtree_size: 6},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
 // CHECK:STDOUT:         {kind: 'VirtualModifier', text: 'virtual'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'H'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'H'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDecl', text: ';', subtree_size: 6},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
 // CHECK:STDOUT:         {kind: 'PrivateModifier', text: 'private'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'v'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'v'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableDecl', text: ';', subtree_size: 6},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
 // CHECK:STDOUT:         {kind: 'ProtectedModifier', text: 'protected'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'v'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'v'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableDecl', text: ';', subtree_size: 6},
diff --git a/toolchain/parse/testdata/function/definition/extern.carbon b/toolchain/parse/testdata/function/definition/extern.carbon
index 3e93334769fe7..606df22adae0c 100644
--- a/toolchain/parse/testdata/function/definition/extern.carbon
+++ b/toolchain/parse/testdata/function/definition/extern.carbon
@@ -21,7 +21,7 @@ extern library "foo" fn G() {}
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
 // CHECK:STDOUT:         {kind: 'ExternModifier', text: 'extern'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'G'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'G'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 6},
@@ -35,7 +35,7 @@ extern library "foo" fn G() {}
 // CHECK:STDOUT:             {kind: 'LibraryName', text: '"foo"'},
 // CHECK:STDOUT:           {kind: 'LibrarySpecifier', text: 'library', subtree_size: 2},
 // CHECK:STDOUT:         {kind: 'ExternModifierWithLibrary', text: 'extern', subtree_size: 3},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'G'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'G'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 8},
diff --git a/toolchain/parse/testdata/function/definition/fail_builtin.carbon b/toolchain/parse/testdata/function/definition/fail_builtin.carbon
index 4635b517a7df2..7f10fe60f6565 100644
--- a/toolchain/parse/testdata/function/definition/fail_builtin.carbon
+++ b/toolchain/parse/testdata/function/definition/fail_builtin.carbon
@@ -29,26 +29,26 @@ fn TestRecoveryFromSpuriousEquals();
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'NotString'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'NotString'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'BuiltinFunctionDefinitionStart', text: '=', subtree_size: 5},
 // CHECK:STDOUT:     {kind: 'BuiltinFunctionDefinition', text: ';', has_error: yes, subtree_size: 6},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'JunkAfterString'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'JunkAfterString'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'BuiltinFunctionDefinitionStart', text: '=', subtree_size: 5},
 // CHECK:STDOUT:       {kind: 'BuiltinName', text: '"hello"'},
 // CHECK:STDOUT:     {kind: 'BuiltinFunctionDefinition', text: ';', has_error: yes, subtree_size: 7},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'SpuriousEquals'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'SpuriousEquals'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'BuiltinFunctionDefinitionStart', text: '=', subtree_size: 5},
 // CHECK:STDOUT:     {kind: 'BuiltinFunctionDefinition', text: '}', has_error: yes, subtree_size: 6},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'TestRecoveryFromSpuriousEquals'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'TestRecoveryFromSpuriousEquals'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ';', subtree_size: 5},
diff --git a/toolchain/parse/testdata/function/definition/fail_identifier_in_statements.carbon b/toolchain/parse/testdata/function/definition/fail_identifier_in_statements.carbon
index 4e81ca5dc1213..bdf83bbc4a200 100644
--- a/toolchain/parse/testdata/function/definition/fail_identifier_in_statements.carbon
+++ b/toolchain/parse/testdata/function/definition/fail_identifier_in_statements.carbon
@@ -21,7 +21,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/function/definition/nested.carbon b/toolchain/parse/testdata/function/definition/nested.carbon
index 5a2c87459e016..bc211d5391d9f 100644
--- a/toolchain/parse/testdata/function/definition/nested.carbon
+++ b/toolchain/parse/testdata/function/definition/nested.carbon
@@ -17,21 +17,21 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:           {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'NamedParams'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameBeforeParams', text: 'NamedParams'},
 // CHECK:STDOUT:             {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:               {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:             {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'TuplePattern', text: ')', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 8},
 // CHECK:STDOUT:       {kind: 'FunctionDefinition', text: '}', subtree_size: 9},
 // CHECK:STDOUT:           {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'PositionalParams'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'PositionalParams'},
 // CHECK:STDOUT:         {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'FunctionDefinition', text: '}', subtree_size: 4},
 // CHECK:STDOUT:     {kind: 'FunctionDefinition', text: '}', subtree_size: 19},
diff --git a/toolchain/parse/testdata/function/definition/with_params.carbon b/toolchain/parse/testdata/function/definition/with_params.carbon
index 99ee0a14a4ac9..ffe39fe33b039 100644
--- a/toolchain/parse/testdata/function/definition/with_params.carbon
+++ b/toolchain/parse/testdata/function/definition/with_params.carbon
@@ -16,13 +16,13 @@ fn foo(bar: i64, baz: i64) {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'foo'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'foo'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'bar'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'bar'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i64'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'baz'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'baz'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i64'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 9},
diff --git a/toolchain/parse/testdata/function/definition/with_return_type.carbon b/toolchain/parse/testdata/function/definition/with_return_type.carbon
index 76cc6b90fe281..bc54fe60c9bcc 100644
--- a/toolchain/parse/testdata/function/definition/with_return_type.carbon
+++ b/toolchain/parse/testdata/function/definition/with_return_type.carbon
@@ -16,7 +16,7 @@ fn foo() -> f64 {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'foo'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'foo'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'FloatTypeLiteral', text: 'f64'},
diff --git a/toolchain/parse/testdata/generics/deduced_params/empty.carbon b/toolchain/parse/testdata/generics/deduced_params/empty.carbon
index 278299b70916b..37cebd9b7c77a 100644
--- a/toolchain/parse/testdata/generics/deduced_params/empty.carbon
+++ b/toolchain/parse/testdata/generics/deduced_params/empty.carbon
@@ -16,14 +16,14 @@ interface Bar[]() {}
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:         {kind: 'ImplicitParamListStart', text: '['},
 // CHECK:STDOUT:       {kind: 'ImplicitParamList', text: ']', subtree_size: 2},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'ClassDecl', text: ';', subtree_size: 7},
 // CHECK:STDOUT:         {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Bar'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'Bar'},
 // CHECK:STDOUT:           {kind: 'ImplicitParamListStart', text: '['},
 // CHECK:STDOUT:         {kind: 'ImplicitParamList', text: ']', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
diff --git a/toolchain/parse/testdata/generics/deduced_params/fail_no_parens.carbon b/toolchain/parse/testdata/generics/deduced_params/fail_no_parens.carbon
index ca092fc909ab0..6df47948ff42c 100644
--- a/toolchain/parse/testdata/generics/deduced_params/fail_no_parens.carbon
+++ b/toolchain/parse/testdata/generics/deduced_params/fail_no_parens.carbon
@@ -35,27 +35,27 @@ interface Bar[a: i32] {}
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:         {kind: 'ImplicitParamListStart', text: '['},
 // CHECK:STDOUT:       {kind: 'ImplicitParamList', text: ']', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'ClassDecl', text: ';', has_error: yes, subtree_size: 5},
 // CHECK:STDOUT:       {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:         {kind: 'ImplicitParamListStart', text: '['},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ImplicitParamList', text: ']', subtree_size: 5},
 // CHECK:STDOUT:     {kind: 'ClassDecl', text: ';', has_error: yes, subtree_size: 8},
 // CHECK:STDOUT:       {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Bar'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'Bar'},
 // CHECK:STDOUT:         {kind: 'ImplicitParamListStart', text: '['},
 // CHECK:STDOUT:       {kind: 'ImplicitParamList', text: ']', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'InterfaceDecl', text: '}', has_error: yes, subtree_size: 5},
 // CHECK:STDOUT:       {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Bar'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'Bar'},
 // CHECK:STDOUT:         {kind: 'ImplicitParamListStart', text: '['},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ImplicitParamList', text: ']', subtree_size: 5},
diff --git a/toolchain/parse/testdata/generics/deduced_params/one.carbon b/toolchain/parse/testdata/generics/deduced_params/one.carbon
index 3f42add1cfe78..92578896c924a 100644
--- a/toolchain/parse/testdata/generics/deduced_params/one.carbon
+++ b/toolchain/parse/testdata/generics/deduced_params/one.carbon
@@ -16,9 +16,9 @@ interface Bar[a: i32]() {}
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:         {kind: 'ImplicitParamListStart', text: '['},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ImplicitParamList', text: ']', subtree_size: 5},
@@ -26,9 +26,9 @@ interface Bar[a: i32]() {}
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'ClassDecl', text: ';', subtree_size: 10},
 // CHECK:STDOUT:         {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Bar'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'Bar'},
 // CHECK:STDOUT:           {kind: 'ImplicitParamListStart', text: '['},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'ImplicitParamList', text: ']', subtree_size: 5},
diff --git a/toolchain/parse/testdata/generics/deduced_params/one_suffix_comma.carbon b/toolchain/parse/testdata/generics/deduced_params/one_suffix_comma.carbon
index 67777012f7078..20acc1b32f073 100644
--- a/toolchain/parse/testdata/generics/deduced_params/one_suffix_comma.carbon
+++ b/toolchain/parse/testdata/generics/deduced_params/one_suffix_comma.carbon
@@ -16,9 +16,9 @@ interface Bar[a: i32,]() {}
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:         {kind: 'ImplicitParamListStart', text: '['},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'PatternListComma', text: ','},
@@ -27,9 +27,9 @@ interface Bar[a: i32,]() {}
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'ClassDecl', text: ';', subtree_size: 11},
 // CHECK:STDOUT:         {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Bar'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'Bar'},
 // CHECK:STDOUT:           {kind: 'ImplicitParamListStart', text: '['},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'PatternListComma', text: ','},
diff --git a/toolchain/parse/testdata/generics/deduced_params/six.carbon b/toolchain/parse/testdata/generics/deduced_params/six.carbon
index f550d44f4f7bc..97a747bc829c0 100644
--- a/toolchain/parse/testdata/generics/deduced_params/six.carbon
+++ b/toolchain/parse/testdata/generics/deduced_params/six.carbon
@@ -16,29 +16,29 @@ interface Bar[a: i32, b: i32, c: i32, d: i32, e: i32, f: i32]() {}
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:         {kind: 'ImplicitParamListStart', text: '['},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'c'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'c'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'd'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'd'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'e'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'e'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'f'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'f'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ImplicitParamList', text: ']', subtree_size: 25},
@@ -46,29 +46,29 @@ interface Bar[a: i32, b: i32, c: i32, d: i32, e: i32, f: i32]() {}
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'ClassDecl', text: ';', subtree_size: 30},
 // CHECK:STDOUT:         {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Bar'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'Bar'},
 // CHECK:STDOUT:           {kind: 'ImplicitParamListStart', text: '['},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'c'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'c'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'd'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'd'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'e'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'e'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'f'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'f'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'ImplicitParamList', text: ']', subtree_size: 25},
diff --git a/toolchain/parse/testdata/generics/deduced_params/two.carbon b/toolchain/parse/testdata/generics/deduced_params/two.carbon
index d06effbb7ca0d..30626bbe634d1 100644
--- a/toolchain/parse/testdata/generics/deduced_params/two.carbon
+++ b/toolchain/parse/testdata/generics/deduced_params/two.carbon
@@ -16,13 +16,13 @@ interface Bar[a: i32, b: i32]() {}
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:         {kind: 'ImplicitParamListStart', text: '['},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ImplicitParamList', text: ']', subtree_size: 9},
@@ -30,13 +30,13 @@ interface Bar[a: i32, b: i32]() {}
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'ClassDecl', text: ';', subtree_size: 14},
 // CHECK:STDOUT:         {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Bar'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'Bar'},
 // CHECK:STDOUT:           {kind: 'ImplicitParamListStart', text: '['},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'ImplicitParamList', text: ']', subtree_size: 9},
diff --git a/toolchain/parse/testdata/generics/deduced_params/two_suffix_comma.carbon b/toolchain/parse/testdata/generics/deduced_params/two_suffix_comma.carbon
index c784c48c8c74e..3155269d16d3f 100644
--- a/toolchain/parse/testdata/generics/deduced_params/two_suffix_comma.carbon
+++ b/toolchain/parse/testdata/generics/deduced_params/two_suffix_comma.carbon
@@ -16,13 +16,13 @@ interface Bar[a: i32, b: i32,]() {}
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:         {kind: 'ImplicitParamListStart', text: '['},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'PatternListComma', text: ','},
@@ -31,13 +31,13 @@ interface Bar[a: i32, b: i32,]() {}
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'ClassDecl', text: ';', subtree_size: 15},
 // CHECK:STDOUT:         {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Bar'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'Bar'},
 // CHECK:STDOUT:           {kind: 'ImplicitParamListStart', text: '['},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'PatternListComma', text: ','},
diff --git a/toolchain/parse/testdata/generics/generic_params/basic.carbon b/toolchain/parse/testdata/generics/generic_params/basic.carbon
index 688aa4cf86254..d5a44ae3bc2e0 100644
--- a/toolchain/parse/testdata/generics/generic_params/basic.carbon
+++ b/toolchain/parse/testdata/generics/generic_params/basic.carbon
@@ -14,9 +14,9 @@ fn foo(a:! i32);
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'foo'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'CompileTimeBindingPattern', text: ':!', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 5},
diff --git a/toolchain/parse/testdata/generics/generic_params/template.carbon b/toolchain/parse/testdata/generics/generic_params/template.carbon
index 7960c4182193b..080f78a4aa3d5 100644
--- a/toolchain/parse/testdata/generics/generic_params/template.carbon
+++ b/toolchain/parse/testdata/generics/generic_params/template.carbon
@@ -14,9 +14,9 @@ fn foo(template a:! i32);
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'foo'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'CompileTimeBindingPattern', text: ':!', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'Template', text: 'template', subtree_size: 4},
diff --git a/toolchain/parse/testdata/generics/generic_params/template_addr.carbon b/toolchain/parse/testdata/generics/generic_params/template_addr.carbon
index 2ec44ec820f26..9407d769f935d 100644
--- a/toolchain/parse/testdata/generics/generic_params/template_addr.carbon
+++ b/toolchain/parse/testdata/generics/generic_params/template_addr.carbon
@@ -14,9 +14,9 @@ fn foo(template addr a:! i32);
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'foo'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:               {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:             {kind: 'CompileTimeBindingPattern', text: ':!', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'Addr', text: 'addr', subtree_size: 4},
diff --git a/toolchain/parse/testdata/generics/impl/basic.carbon b/toolchain/parse/testdata/generics/impl/basic.carbon
index 9119025057c51..1c2728820fbc0 100644
--- a/toolchain/parse/testdata/generics/impl/basic.carbon
+++ b/toolchain/parse/testdata/generics/impl/basic.carbon
@@ -21,14 +21,14 @@ impl i32 as Interface {
 // CHECK:STDOUT:         {kind: 'IdentifierNameExpr', text: 'Interface'},
 // CHECK:STDOUT:       {kind: 'ImplDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Add'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'Add'},
 // CHECK:STDOUT:           {kind: 'ImplicitParamListStart', text: '['},
 // CHECK:STDOUT:             {kind: 'SelfValueName', text: 'self'},
 // CHECK:STDOUT:             {kind: 'SelfTypeNameExpr', text: 'Self'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'ImplicitParamList', text: ']', subtree_size: 5},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:             {kind: 'SelfTypeNameExpr', text: 'Self'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 5},
diff --git a/toolchain/parse/testdata/generics/impl/class.carbon b/toolchain/parse/testdata/generics/impl/class.carbon
index ce769317e28a0..3ab0f6ceb2f5e 100644
--- a/toolchain/parse/testdata/generics/impl/class.carbon
+++ b/toolchain/parse/testdata/generics/impl/class.carbon
@@ -23,7 +23,7 @@ class C {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'C'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'C'},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'ImplIntroducer', text: 'impl'},
 // CHECK:STDOUT:         {kind: 'DefaultSelfImplAs', text: 'as'},
@@ -46,7 +46,7 @@ class C {
 // CHECK:STDOUT:           {kind: 'IdentifierNameExpr', text: 'ExtendImpl'},
 // CHECK:STDOUT:         {kind: 'ImplDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:           {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:             {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:           {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:         {kind: 'FunctionDecl', text: ';', subtree_size: 5},
diff --git a/toolchain/parse/testdata/generics/impl/fail_impl.carbon b/toolchain/parse/testdata/generics/impl/fail_impl.carbon
index bf3405624980f..64b0a695f5917 100644
--- a/toolchain/parse/testdata/generics/impl/fail_impl.carbon
+++ b/toolchain/parse/testdata/generics/impl/fail_impl.carbon
@@ -134,7 +134,7 @@ impl
 // CHECK:STDOUT:     {kind: 'ImplDecl', text: ';', has_error: yes, subtree_size: 6},
 // CHECK:STDOUT:       {kind: 'ImplIntroducer', text: 'impl'},
 // CHECK:STDOUT:           {kind: 'ImplicitParamListStart', text: '['},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'invalid'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'invalid'},
 // CHECK:STDOUT:             {kind: 'InvalidParse', text: ']', has_error: yes},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: 'invalid', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'ImplicitParamList', text: ']', has_error: yes, subtree_size: 5},
@@ -150,7 +150,7 @@ impl
 // CHECK:STDOUT:     {kind: 'ImplDecl', text: ';', has_error: yes, subtree_size: 7},
 // CHECK:STDOUT:       {kind: 'ImplIntroducer', text: 'impl'},
 // CHECK:STDOUT:           {kind: 'ImplicitParamListStart', text: '['},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'T'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'T'},
 // CHECK:STDOUT:             {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:           {kind: 'CompileTimeBindingPattern', text: ':!', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'ImplicitParamList', text: ']', subtree_size: 5},
@@ -159,7 +159,7 @@ impl
 // CHECK:STDOUT:     {kind: 'ImplDecl', text: ';', has_error: yes, subtree_size: 9},
 // CHECK:STDOUT:       {kind: 'ImplIntroducer', text: 'impl'},
 // CHECK:STDOUT:           {kind: 'ImplicitParamListStart', text: '['},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'T'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'T'},
 // CHECK:STDOUT:             {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:           {kind: 'CompileTimeBindingPattern', text: ':!', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'ImplicitParamList', text: ']', subtree_size: 5},
@@ -168,7 +168,7 @@ impl
 // CHECK:STDOUT:     {kind: 'ImplDecl', text: ';', has_error: yes, subtree_size: 9},
 // CHECK:STDOUT:       {kind: 'ImplIntroducer', text: 'impl'},
 // CHECK:STDOUT:           {kind: 'ImplicitParamListStart', text: '['},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'T'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'T'},
 // CHECK:STDOUT:             {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:           {kind: 'CompileTimeBindingPattern', text: ':!', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'ImplicitParamList', text: ']', subtree_size: 5},
diff --git a/toolchain/parse/testdata/generics/impl/fail_out_of_line_member.carbon b/toolchain/parse/testdata/generics/impl/fail_out_of_line_member.carbon
index bdaf57c37d08b..63fb4337720e9 100644
--- a/toolchain/parse/testdata/generics/impl/fail_out_of_line_member.carbon
+++ b/toolchain/parse/testdata/generics/impl/fail_out_of_line_member.carbon
@@ -39,10 +39,10 @@ fn C.(Self as Interface).F() {}
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Interface'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'Interface'},
 // CHECK:STDOUT:       {kind: 'InterfaceDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDecl', text: ';', subtree_size: 5},
@@ -53,7 +53,7 @@ fn C.(Self as Interface).F() {}
 // CHECK:STDOUT:         {kind: 'IdentifierNameExpr', text: 'Interface'},
 // CHECK:STDOUT:       {kind: 'ImplDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDecl', text: ';', subtree_size: 5},
@@ -62,7 +62,7 @@ fn C.(Self as Interface).F() {}
 // CHECK:STDOUT:       {kind: 'InvalidParse', text: '(', has_error: yes},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: '}', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'C'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'C'},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'ImplIntroducer', text: 'impl'},
 // CHECK:STDOUT:             {kind: 'SelfTypeNameExpr', text: 'Self'},
@@ -70,15 +70,15 @@ fn C.(Self as Interface).F() {}
 // CHECK:STDOUT:           {kind: 'IdentifierNameExpr', text: 'Interface'},
 // CHECK:STDOUT:         {kind: 'ImplDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:           {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:             {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:           {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:         {kind: 'FunctionDecl', text: ';', subtree_size: 5},
 // CHECK:STDOUT:       {kind: 'ImplDefinition', text: '}', subtree_size: 11},
 // CHECK:STDOUT:     {kind: 'ClassDefinition', text: '}', subtree_size: 15},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'C'},
-// CHECK:STDOUT:       {kind: 'NameQualifier', text: '.', subtree_size: 2},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'C'},
+// CHECK:STDOUT:       {kind: 'NameQualifierWithoutParams', text: '.', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'InvalidParse', text: '(', has_error: yes},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: '}', has_error: yes, subtree_size: 5},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
diff --git a/toolchain/parse/testdata/generics/impl/forall.carbon b/toolchain/parse/testdata/generics/impl/forall.carbon
index 83c7b079b4de4..21da7a1ec9b76 100644
--- a/toolchain/parse/testdata/generics/impl/forall.carbon
+++ b/toolchain/parse/testdata/generics/impl/forall.carbon
@@ -18,7 +18,7 @@ impl forall [T:! type, U:! Interface] U as Interface(T) {
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'ImplIntroducer', text: 'impl'},
 // CHECK:STDOUT:           {kind: 'ImplicitParamListStart', text: '['},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'T'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'T'},
 // CHECK:STDOUT:             {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:           {kind: 'CompileTimeBindingPattern', text: ':!', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'ImplicitParamList', text: ']', subtree_size: 5},
@@ -29,11 +29,11 @@ impl forall [T:! type, U:! Interface] U as Interface(T) {
 // CHECK:STDOUT:     {kind: 'ImplDecl', text: ';', subtree_size: 11},
 // CHECK:STDOUT:         {kind: 'ImplIntroducer', text: 'impl'},
 // CHECK:STDOUT:             {kind: 'ImplicitParamListStart', text: '['},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'T'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'T'},
 // CHECK:STDOUT:               {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:             {kind: 'CompileTimeBindingPattern', text: ':!', subtree_size: 3},
 // CHECK:STDOUT:             {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'U'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'U'},
 // CHECK:STDOUT:               {kind: 'IdentifierNameExpr', text: 'Interface'},
 // CHECK:STDOUT:             {kind: 'CompileTimeBindingPattern', text: ':!', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'ImplicitParamList', text: ']', subtree_size: 9},
diff --git a/toolchain/parse/testdata/generics/interface/associated_constants.carbon b/toolchain/parse/testdata/generics/interface/associated_constants.carbon
index 1db31cc4facdf..13a33414ce09b 100644
--- a/toolchain/parse/testdata/generics/interface/associated_constants.carbon
+++ b/toolchain/parse/testdata/generics/interface/associated_constants.carbon
@@ -19,11 +19,11 @@ interface Foo {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:       {kind: 'InterfaceDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'LetIntroducer', text: 'let'},
 // CHECK:STDOUT:         {kind: 'FinalModifier', text: 'final'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'I'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'I'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'LetInitializer', text: '='},
@@ -31,7 +31,7 @@ interface Foo {
 // CHECK:STDOUT:       {kind: 'LetDecl', text: ';', subtree_size: 8},
 // CHECK:STDOUT:         {kind: 'LetIntroducer', text: 'let'},
 // CHECK:STDOUT:         {kind: 'DefaultModifier', text: 'default'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'D'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'D'},
 // CHECK:STDOUT:           {kind: 'BoolTypeLiteral', text: 'bool'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'LetInitializer', text: '='},
diff --git a/toolchain/parse/testdata/generics/interface/basic.carbon b/toolchain/parse/testdata/generics/interface/basic.carbon
index 3afb30e2cae05..7f940a21a27d5 100644
--- a/toolchain/parse/testdata/generics/interface/basic.carbon
+++ b/toolchain/parse/testdata/generics/interface/basic.carbon
@@ -17,17 +17,17 @@ interface Foo {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:       {kind: 'InterfaceDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Add'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'Add'},
 // CHECK:STDOUT:           {kind: 'ImplicitParamListStart', text: '['},
 // CHECK:STDOUT:             {kind: 'SelfValueName', text: 'self'},
 // CHECK:STDOUT:             {kind: 'SelfTypeNameExpr', text: 'Self'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'ImplicitParamList', text: ']', subtree_size: 5},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:             {kind: 'SelfTypeNameExpr', text: 'Self'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 5},
@@ -35,14 +35,14 @@ interface Foo {
 // CHECK:STDOUT:         {kind: 'ReturnType', text: '->', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDecl', text: ';', subtree_size: 15},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Add'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'Add'},
 // CHECK:STDOUT:           {kind: 'ImplicitParamListStart', text: '['},
 // CHECK:STDOUT:             {kind: 'SelfValueName', text: 'self'},
 // CHECK:STDOUT:             {kind: 'IdentifierNameExpr', text: 'foo'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'ImplicitParamList', text: ']', subtree_size: 5},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:             {kind: 'SelfTypeNameExpr', text: 'Self'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 5},
diff --git a/toolchain/parse/testdata/generics/interface/declaration.carbon b/toolchain/parse/testdata/generics/interface/declaration.carbon
index 7860157e60c79..820c0edd3384a 100644
--- a/toolchain/parse/testdata/generics/interface/declaration.carbon
+++ b/toolchain/parse/testdata/generics/interface/declaration.carbon
@@ -14,7 +14,7 @@ interface Foo;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:     {kind: 'InterfaceDecl', text: ';', subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
 // CHECK:STDOUT:   ]
diff --git a/toolchain/parse/testdata/generics/interface/default_fn.carbon b/toolchain/parse/testdata/generics/interface/default_fn.carbon
index 386cbe2556f6d..f8c275fb16381 100644
--- a/toolchain/parse/testdata/generics/interface/default_fn.carbon
+++ b/toolchain/parse/testdata/generics/interface/default_fn.carbon
@@ -21,17 +21,17 @@ interface Foo {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:       {kind: 'InterfaceDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Scale'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'Scale'},
 // CHECK:STDOUT:           {kind: 'ImplicitParamListStart', text: '['},
 // CHECK:STDOUT:             {kind: 'SelfValueName', text: 'self'},
 // CHECK:STDOUT:             {kind: 'SelfTypeNameExpr', text: 'Self'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'ImplicitParamList', text: ']', subtree_size: 5},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 's'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 's'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 5},
@@ -40,7 +40,7 @@ interface Foo {
 // CHECK:STDOUT:       {kind: 'FunctionDecl', text: ';', subtree_size: 15},
 // CHECK:STDOUT:           {kind: 'FunctionIntroducer', text: 'fn'},
 // CHECK:STDOUT:           {kind: 'DefaultModifier', text: 'default'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'Invert'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameBeforeParams', text: 'Invert'},
 // CHECK:STDOUT:             {kind: 'ImplicitParamListStart', text: '['},
 // CHECK:STDOUT:               {kind: 'SelfValueName', text: 'self'},
 // CHECK:STDOUT:               {kind: 'SelfTypeNameExpr', text: 'Self'},
@@ -53,7 +53,7 @@ interface Foo {
 // CHECK:STDOUT:         {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 13},
 // CHECK:STDOUT:           {kind: 'ReturnStatementStart', text: 'return'},
 // CHECK:STDOUT:                 {kind: 'SelfValueNameExpr', text: 'self'},
-// CHECK:STDOUT:                 {kind: 'IdentifierName', text: 'Scale'},
+// CHECK:STDOUT:                 {kind: 'IdentifierNameNotBeforeParams', text: 'Scale'},
 // CHECK:STDOUT:               {kind: 'MemberAccessExpr', text: '.', subtree_size: 3},
 // CHECK:STDOUT:             {kind: 'CallExprStart', text: '(', subtree_size: 4},
 // CHECK:STDOUT:               {kind: 'IntLiteral', text: '1'},
diff --git a/toolchain/parse/testdata/generics/interface/empty_body.carbon b/toolchain/parse/testdata/generics/interface/empty_body.carbon
index f2d15d68146bd..97fe9514800ba 100644
--- a/toolchain/parse/testdata/generics/interface/empty_body.carbon
+++ b/toolchain/parse/testdata/generics/interface/empty_body.carbon
@@ -15,7 +15,7 @@ interface Foo {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:       {kind: 'InterfaceDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'InterfaceDefinition', text: '}', subtree_size: 4},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
diff --git a/toolchain/parse/testdata/generics/interface/fail_missing_open_curly.carbon b/toolchain/parse/testdata/generics/interface/fail_missing_open_curly.carbon
index d679936c944e5..92dc39cc1af0e 100644
--- a/toolchain/parse/testdata/generics/interface/fail_missing_open_curly.carbon
+++ b/toolchain/parse/testdata/generics/interface/fail_missing_open_curly.carbon
@@ -23,10 +23,10 @@ interface Foo
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Bar'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'Bar'},
 // CHECK:STDOUT:     {kind: 'InterfaceDecl', text: '}', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:     {kind: 'InterfaceDecl', text: 'Foo', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
 // CHECK:STDOUT:   ]
diff --git a/toolchain/parse/testdata/generics/interface/fail_self_param_syntax.carbon b/toolchain/parse/testdata/generics/interface/fail_self_param_syntax.carbon
index 5fb82dc3ea8bf..49f0f76a88e16 100644
--- a/toolchain/parse/testdata/generics/interface/fail_self_param_syntax.carbon
+++ b/toolchain/parse/testdata/generics/interface/fail_self_param_syntax.carbon
@@ -25,17 +25,17 @@ interface Foo {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:       {kind: 'InterfaceDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Sub'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'Sub'},
 // CHECK:STDOUT:           {kind: 'ImplicitParamListStart', text: '['},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'me'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'me'},
 // CHECK:STDOUT:             {kind: 'InvalidParse', text: 'Self', has_error: yes},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: 'me', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'ImplicitParamList', text: ']', has_error: yes, subtree_size: 5},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:             {kind: 'SelfTypeNameExpr', text: 'Self'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 5},
@@ -43,14 +43,14 @@ interface Foo {
 // CHECK:STDOUT:         {kind: 'ReturnType', text: '->', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDecl', text: ';', subtree_size: 15},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Mul'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'Mul'},
 // CHECK:STDOUT:           {kind: 'ImplicitParamListStart', text: '['},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'Self', has_error: yes},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'Self', has_error: yes},
 // CHECK:STDOUT:             {kind: 'InvalidParse', text: 'Self', has_error: yes},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: 'Self', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'ImplicitParamList', text: ']', has_error: yes, subtree_size: 5},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:             {kind: 'SelfTypeNameExpr', text: 'Self'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 5},
diff --git a/toolchain/parse/testdata/generics/interface/final_fn.carbon b/toolchain/parse/testdata/generics/interface/final_fn.carbon
index d77f43424829a..0d60eb6382942 100644
--- a/toolchain/parse/testdata/generics/interface/final_fn.carbon
+++ b/toolchain/parse/testdata/generics/interface/final_fn.carbon
@@ -19,17 +19,17 @@ interface Order {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Order'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'Order'},
 // CHECK:STDOUT:       {kind: 'InterfaceDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Less'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'Less'},
 // CHECK:STDOUT:           {kind: 'ImplicitParamListStart', text: '['},
 // CHECK:STDOUT:             {kind: 'SelfValueName', text: 'self'},
 // CHECK:STDOUT:             {kind: 'SelfTypeNameExpr', text: 'Self'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'ImplicitParamList', text: ']', subtree_size: 5},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'right'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'right'},
 // CHECK:STDOUT:             {kind: 'SelfTypeNameExpr', text: 'Self'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 5},
@@ -38,14 +38,14 @@ interface Order {
 // CHECK:STDOUT:       {kind: 'FunctionDecl', text: ';', subtree_size: 15},
 // CHECK:STDOUT:           {kind: 'FunctionIntroducer', text: 'fn'},
 // CHECK:STDOUT:           {kind: 'FinalModifier', text: 'final'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'Greater'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameBeforeParams', text: 'Greater'},
 // CHECK:STDOUT:             {kind: 'ImplicitParamListStart', text: '['},
 // CHECK:STDOUT:               {kind: 'SelfValueName', text: 'self'},
 // CHECK:STDOUT:               {kind: 'SelfTypeNameExpr', text: 'Self'},
 // CHECK:STDOUT:             {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'ImplicitParamList', text: ']', subtree_size: 5},
 // CHECK:STDOUT:             {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'right'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'right'},
 // CHECK:STDOUT:               {kind: 'SelfTypeNameExpr', text: 'Self'},
 // CHECK:STDOUT:             {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'TuplePattern', text: ')', subtree_size: 5},
@@ -54,7 +54,7 @@ interface Order {
 // CHECK:STDOUT:         {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 16},
 // CHECK:STDOUT:           {kind: 'ReturnStatementStart', text: 'return'},
 // CHECK:STDOUT:                 {kind: 'IdentifierNameExpr', text: 'right'},
-// CHECK:STDOUT:                 {kind: 'IdentifierName', text: 'Less'},
+// CHECK:STDOUT:                 {kind: 'IdentifierNameNotBeforeParams', text: 'Less'},
 // CHECK:STDOUT:               {kind: 'MemberAccessExpr', text: '.', subtree_size: 3},
 // CHECK:STDOUT:             {kind: 'CallExprStart', text: '(', subtree_size: 4},
 // CHECK:STDOUT:             {kind: 'SelfValueNameExpr', text: 'self'},
diff --git a/toolchain/parse/testdata/generics/interface/final_member_definition.carbon b/toolchain/parse/testdata/generics/interface/final_member_definition.carbon
index 9b778faa896d1..78b9cffcc8023 100644
--- a/toolchain/parse/testdata/generics/interface/final_member_definition.carbon
+++ b/toolchain/parse/testdata/generics/interface/final_member_definition.carbon
@@ -18,18 +18,18 @@ interface Foo {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:       {kind: 'InterfaceDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'FunctionIntroducer', text: 'fn'},
 // CHECK:STDOUT:           {kind: 'FinalModifier', text: 'final'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'Add'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameBeforeParams', text: 'Add'},
 // CHECK:STDOUT:             {kind: 'ImplicitParamListStart', text: '['},
 // CHECK:STDOUT:               {kind: 'SelfValueName', text: 'self'},
 // CHECK:STDOUT:               {kind: 'SelfTypeNameExpr', text: 'Self'},
 // CHECK:STDOUT:             {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'ImplicitParamList', text: ']', subtree_size: 5},
 // CHECK:STDOUT:             {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:               {kind: 'SelfTypeNameExpr', text: 'Self'},
 // CHECK:STDOUT:             {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'TuplePattern', text: ')', subtree_size: 5},
diff --git a/toolchain/parse/testdata/generics/interface/non_instance_fn.carbon b/toolchain/parse/testdata/generics/interface/non_instance_fn.carbon
index 2755d49715be6..85fc80d0df5a9 100644
--- a/toolchain/parse/testdata/generics/interface/non_instance_fn.carbon
+++ b/toolchain/parse/testdata/generics/interface/non_instance_fn.carbon
@@ -16,10 +16,10 @@ interface Foo {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:       {kind: 'InterfaceDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'FooFactory'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'FooFactory'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'SelfTypeNameExpr', text: 'Self'},
diff --git a/toolchain/parse/testdata/generics/interface/self_pointer.carbon b/toolchain/parse/testdata/generics/interface/self_pointer.carbon
index 3af42ee70c2bc..4cf6e786ac11a 100644
--- a/toolchain/parse/testdata/generics/interface/self_pointer.carbon
+++ b/toolchain/parse/testdata/generics/interface/self_pointer.carbon
@@ -17,10 +17,10 @@ interface Foo {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:       {kind: 'InterfaceDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Sub'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'Sub'},
 // CHECK:STDOUT:           {kind: 'ImplicitParamListStart', text: '['},
 // CHECK:STDOUT:               {kind: 'SelfValueName', text: 'self'},
 // CHECK:STDOUT:                 {kind: 'SelfTypeNameExpr', text: 'Self'},
@@ -29,7 +29,7 @@ interface Foo {
 // CHECK:STDOUT:           {kind: 'Addr', text: 'addr', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'ImplicitParamList', text: ']', subtree_size: 7},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:             {kind: 'SelfTypeNameExpr', text: 'Self'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 5},
@@ -37,7 +37,7 @@ interface Foo {
 // CHECK:STDOUT:         {kind: 'ReturnType', text: '->', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDecl', text: ';', subtree_size: 17},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Sub'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'Sub'},
 // CHECK:STDOUT:           {kind: 'ImplicitParamListStart', text: '['},
 // CHECK:STDOUT:               {kind: 'SelfValueName', text: 'self'},
 // CHECK:STDOUT:                 {kind: 'IdentifierNameExpr', text: 'foo'},
@@ -46,7 +46,7 @@ interface Foo {
 // CHECK:STDOUT:           {kind: 'Addr', text: 'addr', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'ImplicitParamList', text: ']', subtree_size: 7},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:             {kind: 'SelfTypeNameExpr', text: 'Self'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 5},
diff --git a/toolchain/parse/testdata/generics/named_constraint/basic.carbon b/toolchain/parse/testdata/generics/named_constraint/basic.carbon
index 67c82b56a8b19..f11b73a3cdafa 100644
--- a/toolchain/parse/testdata/generics/named_constraint/basic.carbon
+++ b/toolchain/parse/testdata/generics/named_constraint/basic.carbon
@@ -18,16 +18,16 @@ constraint ForwardDeclared;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'NamedConstraintIntroducer', text: 'constraint'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:       {kind: 'NamedConstraintDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Baz'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'Baz'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDecl', text: ';', subtree_size: 5},
 // CHECK:STDOUT:     {kind: 'NamedConstraintDefinition', text: '}', subtree_size: 9},
 // CHECK:STDOUT:       {kind: 'NamedConstraintIntroducer', text: 'constraint'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'ForwardDeclared'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'ForwardDeclared'},
 // CHECK:STDOUT:     {kind: 'NamedConstraintDecl', text: ';', subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
 // CHECK:STDOUT:   ]
diff --git a/toolchain/parse/testdata/generics/named_constraint/defined_method.carbon b/toolchain/parse/testdata/generics/named_constraint/defined_method.carbon
index 27859247b6517..0378ac7371946 100644
--- a/toolchain/parse/testdata/generics/named_constraint/defined_method.carbon
+++ b/toolchain/parse/testdata/generics/named_constraint/defined_method.carbon
@@ -16,17 +16,17 @@ constraint Foo {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'NamedConstraintIntroducer', text: 'constraint'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:       {kind: 'NamedConstraintDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'Add'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameBeforeParams', text: 'Add'},
 // CHECK:STDOUT:             {kind: 'ImplicitParamListStart', text: '['},
 // CHECK:STDOUT:               {kind: 'SelfValueName', text: 'self'},
 // CHECK:STDOUT:               {kind: 'SelfTypeNameExpr', text: 'Self'},
 // CHECK:STDOUT:             {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'ImplicitParamList', text: ']', subtree_size: 5},
 // CHECK:STDOUT:             {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:               {kind: 'SelfTypeNameExpr', text: 'Self'},
 // CHECK:STDOUT:             {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'TuplePattern', text: ')', subtree_size: 5},
diff --git a/toolchain/parse/testdata/generics/params/empty.carbon b/toolchain/parse/testdata/generics/params/empty.carbon
index e3806b5e0f407..55e3f97e0338e 100644
--- a/toolchain/parse/testdata/generics/params/empty.carbon
+++ b/toolchain/parse/testdata/generics/params/empty.carbon
@@ -16,12 +16,12 @@ interface Bar() {}
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'ClassDecl', text: ';', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Bar'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'Bar'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'InterfaceDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/generics/params/name_qualifier.carbon b/toolchain/parse/testdata/generics/params/name_qualifier.carbon
index 5e1cc1fa4b5c4..7b4dcdcd341ce 100644
--- a/toolchain/parse/testdata/generics/params/name_qualifier.carbon
+++ b/toolchain/parse/testdata/generics/params/name_qualifier.carbon
@@ -34,136 +34,136 @@ fn OuterGeneric(T:! type).InnerGeneric(U:! type).F(x: T, y: U) {}
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'GenericClass1'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'GenericClass1'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'T'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'T'},
 // CHECK:STDOUT:             {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:           {kind: 'CompileTimeBindingPattern', text: ':!', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 5},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 8},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDecl', text: ';', subtree_size: 5},
 // CHECK:STDOUT:     {kind: 'ClassDefinition', text: '}', subtree_size: 14},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'GenericClass1'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameBeforeParams', text: 'GenericClass1'},
 // CHECK:STDOUT:             {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'T'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'T'},
 // CHECK:STDOUT:               {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:             {kind: 'CompileTimeBindingPattern', text: ':!', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'TuplePattern', text: ')', subtree_size: 5},
-// CHECK:STDOUT:         {kind: 'NameQualifier', text: '.', subtree_size: 7},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'NameQualifierWithParams', text: '.', subtree_size: 7},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 12},
 // CHECK:STDOUT:     {kind: 'FunctionDefinition', text: '}', subtree_size: 13},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'GenericClass2'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'GenericClass2'},
 // CHECK:STDOUT:           {kind: 'ImplicitParamListStart', text: '['},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'T'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'T'},
 // CHECK:STDOUT:             {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:           {kind: 'CompileTimeBindingPattern', text: ':!', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'ImplicitParamList', text: ']', subtree_size: 5},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'X'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'X'},
 // CHECK:STDOUT:             {kind: 'IdentifierNameExpr', text: 'T'},
 // CHECK:STDOUT:           {kind: 'CompileTimeBindingPattern', text: ':!', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 5},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 13},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDecl', text: ';', subtree_size: 5},
 // CHECK:STDOUT:     {kind: 'ClassDefinition', text: '}', subtree_size: 19},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'GenericClass2'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameBeforeParams', text: 'GenericClass2'},
 // CHECK:STDOUT:             {kind: 'ImplicitParamListStart', text: '['},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'T'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'T'},
 // CHECK:STDOUT:               {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:             {kind: 'CompileTimeBindingPattern', text: ':!', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'ImplicitParamList', text: ']', subtree_size: 5},
 // CHECK:STDOUT:             {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'X'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'X'},
 // CHECK:STDOUT:               {kind: 'IdentifierNameExpr', text: 'T'},
 // CHECK:STDOUT:             {kind: 'CompileTimeBindingPattern', text: ':!', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'TuplePattern', text: ')', subtree_size: 5},
-// CHECK:STDOUT:         {kind: 'NameQualifier', text: '.', subtree_size: 12},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'NameQualifierWithParams', text: '.', subtree_size: 12},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 17},
 // CHECK:STDOUT:     {kind: 'FunctionDefinition', text: '}', subtree_size: 18},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'OuterGeneric'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'OuterGeneric'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'T'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'T'},
 // CHECK:STDOUT:             {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:           {kind: 'CompileTimeBindingPattern', text: ':!', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 5},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 8},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'InnerGeneric'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'InnerGeneric'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'U'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'U'},
 // CHECK:STDOUT:             {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:           {kind: 'CompileTimeBindingPattern', text: ':!', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 5},
 // CHECK:STDOUT:       {kind: 'ClassDecl', text: ';', subtree_size: 8},
 // CHECK:STDOUT:     {kind: 'ClassDefinition', text: '}', subtree_size: 17},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'OuterGeneric'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameBeforeParams', text: 'OuterGeneric'},
 // CHECK:STDOUT:             {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'T'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'T'},
 // CHECK:STDOUT:               {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:             {kind: 'CompileTimeBindingPattern', text: ':!', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'TuplePattern', text: ')', subtree_size: 5},
-// CHECK:STDOUT:         {kind: 'NameQualifier', text: '.', subtree_size: 7},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'InnerGeneric'},
+// CHECK:STDOUT:         {kind: 'NameQualifierWithParams', text: '.', subtree_size: 7},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'InnerGeneric'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'U'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'U'},
 // CHECK:STDOUT:             {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:           {kind: 'CompileTimeBindingPattern', text: ':!', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 5},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 15},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:             {kind: 'IdentifierNameExpr', text: 'T'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'y'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'y'},
 // CHECK:STDOUT:             {kind: 'IdentifierNameExpr', text: 'U'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 9},
 // CHECK:STDOUT:       {kind: 'FunctionDecl', text: ';', subtree_size: 12},
 // CHECK:STDOUT:     {kind: 'ClassDefinition', text: '}', subtree_size: 28},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'OuterGeneric'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameBeforeParams', text: 'OuterGeneric'},
 // CHECK:STDOUT:             {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'T'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'T'},
 // CHECK:STDOUT:               {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:             {kind: 'CompileTimeBindingPattern', text: ':!', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'TuplePattern', text: ')', subtree_size: 5},
-// CHECK:STDOUT:         {kind: 'NameQualifier', text: '.', subtree_size: 7},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'InnerGeneric'},
+// CHECK:STDOUT:         {kind: 'NameQualifierWithParams', text: '.', subtree_size: 7},
+// CHECK:STDOUT:           {kind: 'IdentifierNameBeforeParams', text: 'InnerGeneric'},
 // CHECK:STDOUT:             {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'U'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'U'},
 // CHECK:STDOUT:               {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:             {kind: 'CompileTimeBindingPattern', text: ':!', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'TuplePattern', text: ')', subtree_size: 5},
-// CHECK:STDOUT:         {kind: 'NameQualifier', text: '.', subtree_size: 7},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'NameQualifierWithParams', text: '.', subtree_size: 7},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:             {kind: 'IdentifierNameExpr', text: 'T'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'y'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'y'},
 // CHECK:STDOUT:             {kind: 'IdentifierNameExpr', text: 'U'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 9},
diff --git a/toolchain/parse/testdata/generics/params/one.carbon b/toolchain/parse/testdata/generics/params/one.carbon
index 1d68b3072b454..28c580c20a01f 100644
--- a/toolchain/parse/testdata/generics/params/one.carbon
+++ b/toolchain/parse/testdata/generics/params/one.carbon
@@ -16,17 +16,17 @@ interface Bar(a: i32) {}
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 5},
 // CHECK:STDOUT:     {kind: 'ClassDecl', text: ';', subtree_size: 8},
 // CHECK:STDOUT:         {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Bar'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'Bar'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 5},
diff --git a/toolchain/parse/testdata/generics/params/one_suffix_comma.carbon b/toolchain/parse/testdata/generics/params/one_suffix_comma.carbon
index 9f7598a993188..174e139e5dff2 100644
--- a/toolchain/parse/testdata/generics/params/one_suffix_comma.carbon
+++ b/toolchain/parse/testdata/generics/params/one_suffix_comma.carbon
@@ -16,18 +16,18 @@ interface Bar(a: i32,) {}
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'PatternListComma', text: ','},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 6},
 // CHECK:STDOUT:     {kind: 'ClassDecl', text: ';', subtree_size: 9},
 // CHECK:STDOUT:         {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Bar'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'Bar'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'PatternListComma', text: ','},
diff --git a/toolchain/parse/testdata/generics/params/six.carbon b/toolchain/parse/testdata/generics/params/six.carbon
index cad1bb97d1be0..f470b6aec188a 100644
--- a/toolchain/parse/testdata/generics/params/six.carbon
+++ b/toolchain/parse/testdata/generics/params/six.carbon
@@ -16,57 +16,57 @@ interface Bar(a: i32, b: i32, c: i32, d: i32, e: i32, f: i32) {}
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'c'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'c'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'd'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'd'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'e'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'e'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'f'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'f'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 25},
 // CHECK:STDOUT:     {kind: 'ClassDecl', text: ';', subtree_size: 28},
 // CHECK:STDOUT:         {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Bar'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'Bar'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'c'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'c'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'd'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'd'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'e'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'e'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'f'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'f'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 25},
diff --git a/toolchain/parse/testdata/generics/params/two.carbon b/toolchain/parse/testdata/generics/params/two.carbon
index 7b67184f33fcf..6e1113b0da161 100644
--- a/toolchain/parse/testdata/generics/params/two.carbon
+++ b/toolchain/parse/testdata/generics/params/two.carbon
@@ -16,25 +16,25 @@ interface Bar(a: i32, b: i32) {}
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 9},
 // CHECK:STDOUT:     {kind: 'ClassDecl', text: ';', subtree_size: 12},
 // CHECK:STDOUT:         {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Bar'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'Bar'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 9},
diff --git a/toolchain/parse/testdata/generics/params/two_suffix_comma.carbon b/toolchain/parse/testdata/generics/params/two_suffix_comma.carbon
index cc985fd5f66b8..07b18e46e3f6d 100644
--- a/toolchain/parse/testdata/generics/params/two_suffix_comma.carbon
+++ b/toolchain/parse/testdata/generics/params/two_suffix_comma.carbon
@@ -16,26 +16,26 @@ interface Bar(a: i32, b: i32,) {}
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'PatternListComma', text: ','},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 10},
 // CHECK:STDOUT:     {kind: 'ClassDecl', text: ';', subtree_size: 13},
 // CHECK:STDOUT:         {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Bar'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'Bar'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'PatternListComma', text: ','},
diff --git a/toolchain/parse/testdata/if/basic.carbon b/toolchain/parse/testdata/if/basic.carbon
index c03e133c7629b..e7e833329fe2a 100644
--- a/toolchain/parse/testdata/if/basic.carbon
+++ b/toolchain/parse/testdata/if/basic.carbon
@@ -22,7 +22,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/if/else.carbon b/toolchain/parse/testdata/if/else.carbon
index 77dcfc3dbdda3..e92bd09d409c4 100644
--- a/toolchain/parse/testdata/if/else.carbon
+++ b/toolchain/parse/testdata/if/else.carbon
@@ -27,7 +27,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/if/fail_else_unbraced.carbon b/toolchain/parse/testdata/if/fail_else_unbraced.carbon
index 1360b8d6dd12b..e08c62a3cfcb5 100644
--- a/toolchain/parse/testdata/if/fail_else_unbraced.carbon
+++ b/toolchain/parse/testdata/if/fail_else_unbraced.carbon
@@ -40,7 +40,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/if/fail_errors.carbon b/toolchain/parse/testdata/if/fail_errors.carbon
index c22a2866a69e4..c5de9be55b7a1 100644
--- a/toolchain/parse/testdata/if/fail_errors.carbon
+++ b/toolchain/parse/testdata/if/fail_errors.carbon
@@ -38,7 +38,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/if/fail_missing_cond.carbon b/toolchain/parse/testdata/if/fail_missing_cond.carbon
index f19ff720b1962..d9a7736013574 100644
--- a/toolchain/parse/testdata/if/fail_missing_cond.carbon
+++ b/toolchain/parse/testdata/if/fail_missing_cond.carbon
@@ -20,7 +20,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/if/fail_square_brackets.carbon b/toolchain/parse/testdata/if/fail_square_brackets.carbon
index cf870ef2b9b63..336b73779bdbe 100644
--- a/toolchain/parse/testdata/if/fail_square_brackets.carbon
+++ b/toolchain/parse/testdata/if/fail_square_brackets.carbon
@@ -27,7 +27,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/if/fail_unbraced.carbon b/toolchain/parse/testdata/if/fail_unbraced.carbon
index 62afe0db4bfac..4633aeaddacb5 100644
--- a/toolchain/parse/testdata/if/fail_unbraced.carbon
+++ b/toolchain/parse/testdata/if/fail_unbraced.carbon
@@ -31,7 +31,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/if_expr/basic.carbon b/toolchain/parse/testdata/if_expr/basic.carbon
index 05d6541294db9..a7aab74871606 100644
--- a/toolchain/parse/testdata/if_expr/basic.carbon
+++ b/toolchain/parse/testdata/if_expr/basic.carbon
@@ -16,17 +16,17 @@ fn F(b: bool, x: i32, y: i32) -> bool {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:             {kind: 'BoolTypeLiteral', text: 'bool'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'y'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'y'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 13},
diff --git a/toolchain/parse/testdata/if_expr/fail_condition_missing.carbon b/toolchain/parse/testdata/if_expr/fail_condition_missing.carbon
index c33341e362497..87310c8f98aec 100644
--- a/toolchain/parse/testdata/if_expr/fail_condition_missing.carbon
+++ b/toolchain/parse/testdata/if_expr/fail_condition_missing.carbon
@@ -19,12 +19,12 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/if_expr/fail_else_expr_missing.carbon b/toolchain/parse/testdata/if_expr/fail_else_expr_missing.carbon
index 3447813a19444..0a2e726d6e3ed 100644
--- a/toolchain/parse/testdata/if_expr/fail_else_expr_missing.carbon
+++ b/toolchain/parse/testdata/if_expr/fail_else_expr_missing.carbon
@@ -19,12 +19,12 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/if_expr/fail_else_missing.carbon b/toolchain/parse/testdata/if_expr/fail_else_missing.carbon
index 408e1b9dbd8cd..4f90f70df290c 100644
--- a/toolchain/parse/testdata/if_expr/fail_else_missing.carbon
+++ b/toolchain/parse/testdata/if_expr/fail_else_missing.carbon
@@ -19,12 +19,12 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/if_expr/fail_then_expr_missing.carbon b/toolchain/parse/testdata/if_expr/fail_then_expr_missing.carbon
index 03136922c3464..35f7d3f5e2c9a 100644
--- a/toolchain/parse/testdata/if_expr/fail_then_expr_missing.carbon
+++ b/toolchain/parse/testdata/if_expr/fail_then_expr_missing.carbon
@@ -19,12 +19,12 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/if_expr/fail_then_missing.carbon b/toolchain/parse/testdata/if_expr/fail_then_missing.carbon
index a8f048ad2b34b..f343f0def9b16 100644
--- a/toolchain/parse/testdata/if_expr/fail_then_missing.carbon
+++ b/toolchain/parse/testdata/if_expr/fail_then_missing.carbon
@@ -19,12 +19,12 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/if_expr/fail_top_level_if.carbon b/toolchain/parse/testdata/if_expr/fail_top_level_if.carbon
index 811aaac5c6279..cd9beb834217f 100644
--- a/toolchain/parse/testdata/if_expr/fail_top_level_if.carbon
+++ b/toolchain/parse/testdata/if_expr/fail_top_level_if.carbon
@@ -27,7 +27,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/if_expr/in_type.carbon b/toolchain/parse/testdata/if_expr/in_type.carbon
index 3df9f2104edbb..09b447059e5ed 100644
--- a/toolchain/parse/testdata/if_expr/in_type.carbon
+++ b/toolchain/parse/testdata/if_expr/in_type.carbon
@@ -18,12 +18,12 @@ fn F() -> if true then i32 else i32* {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'VariableDecl', text: ';', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:               {kind: 'BoolLiteralTrue', text: 'true'},
diff --git a/toolchain/parse/testdata/if_expr/precedence.carbon b/toolchain/parse/testdata/if_expr/precedence.carbon
index be0e896992732..fdb46b51fd944 100644
--- a/toolchain/parse/testdata/if_expr/precedence.carbon
+++ b/toolchain/parse/testdata/if_expr/precedence.carbon
@@ -16,9 +16,9 @@ fn F(b: bool) -> bool {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:             {kind: 'BoolTypeLiteral', text: 'bool'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 5},
diff --git a/toolchain/parse/testdata/index/assign_to_var.carbon b/toolchain/parse/testdata/index/assign_to_var.carbon
index 77f42f7b89dac..86db57a174f4b 100644
--- a/toolchain/parse/testdata/index/assign_to_var.carbon
+++ b/toolchain/parse/testdata/index/assign_to_var.carbon
@@ -14,7 +14,7 @@ var v: i32 = t[0];
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'v'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'v'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/index/fail_empty_expr.carbon b/toolchain/parse/testdata/index/fail_empty_expr.carbon
index 1cf783a0bee3d..e1909fb92450d 100644
--- a/toolchain/parse/testdata/index/fail_empty_expr.carbon
+++ b/toolchain/parse/testdata/index/fail_empty_expr.carbon
@@ -17,7 +17,7 @@ var v: i32 = t[];
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'v'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'v'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/index/fail_malformed_expr.carbon b/toolchain/parse/testdata/index/fail_malformed_expr.carbon
index f7f27eff1a8c4..c836fba8e90d0 100644
--- a/toolchain/parse/testdata/index/fail_malformed_expr.carbon
+++ b/toolchain/parse/testdata/index/fail_malformed_expr.carbon
@@ -17,7 +17,7 @@ var v: i32 = t[0,];
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'v'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'v'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/let/fail_bad_name.carbon b/toolchain/parse/testdata/let/fail_bad_name.carbon
index 071b850b3f4e6..57c15c6306249 100644
--- a/toolchain/parse/testdata/let/fail_bad_name.carbon
+++ b/toolchain/parse/testdata/let/fail_bad_name.carbon
@@ -17,7 +17,7 @@ let ? = 4;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'LetIntroducer', text: 'let'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: '?', has_error: yes},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: '?', has_error: yes},
 // CHECK:STDOUT:         {kind: 'InvalidParse', text: '?', has_error: yes},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: '?', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'LetInitializer', text: '='},
diff --git a/toolchain/parse/testdata/let/fail_empty.carbon b/toolchain/parse/testdata/let/fail_empty.carbon
index 1cb2e09cb407a..1a22b484bdfb5 100644
--- a/toolchain/parse/testdata/let/fail_empty.carbon
+++ b/toolchain/parse/testdata/let/fail_empty.carbon
@@ -17,7 +17,7 @@ let;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'LetIntroducer', text: 'let'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: ';', has_error: yes},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: ';', has_error: yes},
 // CHECK:STDOUT:         {kind: 'InvalidParse', text: ';', has_error: yes},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ';', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'LetDecl', text: ';', subtree_size: 5},
diff --git a/toolchain/parse/testdata/let/fail_missing_name.carbon b/toolchain/parse/testdata/let/fail_missing_name.carbon
index 97c3896f62152..a36e9f8d9ecfd 100644
--- a/toolchain/parse/testdata/let/fail_missing_name.carbon
+++ b/toolchain/parse/testdata/let/fail_missing_name.carbon
@@ -27,7 +27,7 @@ let :! bool = true;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'LetIntroducer', text: 'let'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: ':', has_error: yes},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: ':', has_error: yes},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'LetInitializer', text: '='},
@@ -39,7 +39,7 @@ let :! bool = true;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'LetIntroducer', text: 'let'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: ':!', has_error: yes},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: ':!', has_error: yes},
 // CHECK:STDOUT:         {kind: 'BoolTypeLiteral', text: 'bool'},
 // CHECK:STDOUT:       {kind: 'CompileTimeBindingPattern', text: ':!', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'LetInitializer', text: '='},
diff --git a/toolchain/parse/testdata/let/fail_missing_type.carbon b/toolchain/parse/testdata/let/fail_missing_type.carbon
index 28251537c7325..0ddc3e70de981 100644
--- a/toolchain/parse/testdata/let/fail_missing_type.carbon
+++ b/toolchain/parse/testdata/let/fail_missing_type.carbon
@@ -17,7 +17,7 @@ let a = 4;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'LetIntroducer', text: 'let'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:         {kind: 'InvalidParse', text: '=', has_error: yes},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: 'a', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'LetInitializer', text: '='},
diff --git a/toolchain/parse/testdata/let/fail_no_semi.carbon b/toolchain/parse/testdata/let/fail_no_semi.carbon
index 4d5aa29ce069f..11e3263924398 100644
--- a/toolchain/parse/testdata/let/fail_no_semi.carbon
+++ b/toolchain/parse/testdata/let/fail_no_semi.carbon
@@ -21,7 +21,7 @@ let
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'LetIntroducer', text: 'let'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: '', has_error: yes},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: '', has_error: yes},
 // CHECK:STDOUT:         {kind: 'InvalidParse', text: '', has_error: yes},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: '', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'LetDecl', text: 'let', has_error: yes, subtree_size: 5},
diff --git a/toolchain/parse/testdata/let/let.carbon b/toolchain/parse/testdata/let/let.carbon
index b3409e9d3d83a..08391edac5715 100644
--- a/toolchain/parse/testdata/let/let.carbon
+++ b/toolchain/parse/testdata/let/let.carbon
@@ -17,19 +17,19 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'LetIntroducer', text: 'let'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'v'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'v'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'LetInitializer', text: '='},
 // CHECK:STDOUT:       {kind: 'IntLiteral', text: '0'},
 // CHECK:STDOUT:     {kind: 'LetDecl', text: ';', subtree_size: 7},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'LetIntroducer', text: 'let'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 's'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 's'},
 // CHECK:STDOUT:           {kind: 'StringTypeLiteral', text: 'String'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'LetInitializer', text: '='},
diff --git a/toolchain/parse/testdata/let/let_tuple.carbon b/toolchain/parse/testdata/let/let_tuple.carbon
index afad874bbbde4..9d7a7e5c40f87 100644
--- a/toolchain/parse/testdata/let/let_tuple.carbon
+++ b/toolchain/parse/testdata/let/let_tuple.carbon
@@ -16,17 +16,17 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'LetIntroducer', text: 'let'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 's'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 's'},
 // CHECK:STDOUT:             {kind: 'StringTypeLiteral', text: 'String'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'i'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'i'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 9},
diff --git a/toolchain/parse/testdata/let/missing_value.carbon b/toolchain/parse/testdata/let/missing_value.carbon
index 91392703a5692..0f8487e57a7a4 100644
--- a/toolchain/parse/testdata/let/missing_value.carbon
+++ b/toolchain/parse/testdata/let/missing_value.carbon
@@ -22,26 +22,26 @@ interface I {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'LetIntroducer', text: 'let'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'LetDecl', text: ';', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'LetIntroducer', text: 'let'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'LetDecl', text: ';', subtree_size: 5},
 // CHECK:STDOUT:     {kind: 'FunctionDefinition', text: '}', subtree_size: 11},
 // CHECK:STDOUT:         {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'I'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'I'},
 // CHECK:STDOUT:       {kind: 'InterfaceDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'LetIntroducer', text: 'let'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'T'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'T'},
 // CHECK:STDOUT:           {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:         {kind: 'CompileTimeBindingPattern', text: ':!', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'LetDecl', text: ';', subtree_size: 5},
diff --git a/toolchain/parse/testdata/match/fail_cases_after_default.carbon b/toolchain/parse/testdata/match/fail_cases_after_default.carbon
index 60c41cf305dc2..6a2608ee12e1d 100644
--- a/toolchain/parse/testdata/match/fail_cases_after_default.carbon
+++ b/toolchain/parse/testdata/match/fail_cases_after_default.carbon
@@ -34,14 +34,14 @@ fn f() -> i32 {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'f'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'f'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'ReturnType', text: '->', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 7},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/match/fail_missing_case_arrow.carbon b/toolchain/parse/testdata/match/fail_missing_case_arrow.carbon
index 251e3a81d158b..6174b2d639e6d 100644
--- a/toolchain/parse/testdata/match/fail_missing_case_arrow.carbon
+++ b/toolchain/parse/testdata/match/fail_missing_case_arrow.carbon
@@ -27,7 +27,7 @@ fn f() -> i32 {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'f'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'f'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
@@ -39,14 +39,14 @@ fn f() -> i32 {
 // CHECK:STDOUT:           {kind: 'MatchCondition', text: ')', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'MatchStatementStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:             {kind: 'MatchCaseIntroducer', text: 'case'},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:               {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:             {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:             {kind: 'MatchCaseEqualGreater', text: '{', has_error: yes},
 // CHECK:STDOUT:           {kind: 'MatchCaseStart', text: '{', has_error: yes, subtree_size: 6},
 // CHECK:STDOUT:         {kind: 'MatchCase', text: '{', has_error: yes, subtree_size: 7},
 // CHECK:STDOUT:             {kind: 'MatchCaseIntroducer', text: 'case'},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:               {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:             {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:               {kind: 'MatchCaseGuardIntroducer', text: 'if'},
diff --git a/toolchain/parse/testdata/match/fail_missing_case_pattern.carbon b/toolchain/parse/testdata/match/fail_missing_case_pattern.carbon
index 73c38a2704b10..d3334027b73a4 100644
--- a/toolchain/parse/testdata/match/fail_missing_case_pattern.carbon
+++ b/toolchain/parse/testdata/match/fail_missing_case_pattern.carbon
@@ -22,7 +22,7 @@ fn f() -> i32 {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'f'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'f'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
@@ -34,7 +34,7 @@ fn f() -> i32 {
 // CHECK:STDOUT:           {kind: 'MatchCondition', text: ')', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'MatchStatementStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:             {kind: 'MatchCaseIntroducer', text: 'case'},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: '=>', has_error: yes},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: '=>', has_error: yes},
 // CHECK:STDOUT:               {kind: 'InvalidParse', text: '=>', has_error: yes},
 // CHECK:STDOUT:             {kind: 'BindingPattern', text: '=>', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'MatchCaseStart', text: '=>', has_error: yes, subtree_size: 5},
diff --git a/toolchain/parse/testdata/match/fail_missing_case_statements_block.carbon b/toolchain/parse/testdata/match/fail_missing_case_statements_block.carbon
index 73309391100f9..b42b414513b01 100644
--- a/toolchain/parse/testdata/match/fail_missing_case_statements_block.carbon
+++ b/toolchain/parse/testdata/match/fail_missing_case_statements_block.carbon
@@ -23,7 +23,7 @@ fn f() -> i32 {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'f'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'f'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
@@ -35,7 +35,7 @@ fn f() -> i32 {
 // CHECK:STDOUT:           {kind: 'MatchCondition', text: ')', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'MatchStatementStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:             {kind: 'MatchCaseIntroducer', text: 'case'},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:               {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:             {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:             {kind: 'MatchCaseEqualGreater', text: '=>'},
diff --git a/toolchain/parse/testdata/match/fail_missing_cases.carbon b/toolchain/parse/testdata/match/fail_missing_cases.carbon
index 48bbe366bbf11..aeb9f1a4b77b3 100644
--- a/toolchain/parse/testdata/match/fail_missing_cases.carbon
+++ b/toolchain/parse/testdata/match/fail_missing_cases.carbon
@@ -21,7 +21,7 @@ fn f() -> i32 {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'f'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'f'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
diff --git a/toolchain/parse/testdata/match/fail_missing_cases_block.carbon b/toolchain/parse/testdata/match/fail_missing_cases_block.carbon
index db2610b561d26..8747c189be6f6 100644
--- a/toolchain/parse/testdata/match/fail_missing_cases_block.carbon
+++ b/toolchain/parse/testdata/match/fail_missing_cases_block.carbon
@@ -20,7 +20,7 @@ fn f() -> i32 {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'f'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'f'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
diff --git a/toolchain/parse/testdata/match/fail_missing_default_arrow.carbon b/toolchain/parse/testdata/match/fail_missing_default_arrow.carbon
index ed6d7a37697ed..baca9f9374eca 100644
--- a/toolchain/parse/testdata/match/fail_missing_default_arrow.carbon
+++ b/toolchain/parse/testdata/match/fail_missing_default_arrow.carbon
@@ -22,7 +22,7 @@ fn f() -> i32 {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'f'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'f'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
diff --git a/toolchain/parse/testdata/match/fail_missing_default_statements_block.carbon b/toolchain/parse/testdata/match/fail_missing_default_statements_block.carbon
index 06ae2fc8b6e83..0b89e5865fcc8 100644
--- a/toolchain/parse/testdata/match/fail_missing_default_statements_block.carbon
+++ b/toolchain/parse/testdata/match/fail_missing_default_statements_block.carbon
@@ -22,7 +22,7 @@ fn f() -> i32 {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'f'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'f'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
diff --git a/toolchain/parse/testdata/match/fail_missing_guard_close_paren.carbon b/toolchain/parse/testdata/match/fail_missing_guard_close_paren.carbon
index ef4578057cfaa..bd825b501626b 100644
--- a/toolchain/parse/testdata/match/fail_missing_guard_close_paren.carbon
+++ b/toolchain/parse/testdata/match/fail_missing_guard_close_paren.carbon
@@ -26,7 +26,7 @@ fn f() -> i32 {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'f'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'f'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
@@ -38,7 +38,7 @@ fn f() -> i32 {
 // CHECK:STDOUT:           {kind: 'MatchCondition', text: ')', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'MatchStatementStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:             {kind: 'MatchCaseIntroducer', text: 'case'},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:               {kind: 'BoolTypeLiteral', text: 'bool'},
 // CHECK:STDOUT:             {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:               {kind: 'MatchCaseGuardIntroducer', text: 'if'},
diff --git a/toolchain/parse/testdata/match/fail_missing_guard_open_paren.carbon b/toolchain/parse/testdata/match/fail_missing_guard_open_paren.carbon
index 5ec8859b3afc7..a6cb6cd1e4979 100644
--- a/toolchain/parse/testdata/match/fail_missing_guard_open_paren.carbon
+++ b/toolchain/parse/testdata/match/fail_missing_guard_open_paren.carbon
@@ -26,7 +26,7 @@ fn f() -> i32 {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'f'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'f'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
@@ -38,7 +38,7 @@ fn f() -> i32 {
 // CHECK:STDOUT:           {kind: 'MatchCondition', text: ')', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'MatchStatementStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:             {kind: 'MatchCaseIntroducer', text: 'case'},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:               {kind: 'BoolTypeLiteral', text: 'bool'},
 // CHECK:STDOUT:             {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:               {kind: 'MatchCaseGuardIntroducer', text: 'if'},
diff --git a/toolchain/parse/testdata/match/fail_missing_matched_expr.carbon b/toolchain/parse/testdata/match/fail_missing_matched_expr.carbon
index 75b1004e525f5..36e72b668dcb4 100644
--- a/toolchain/parse/testdata/match/fail_missing_matched_expr.carbon
+++ b/toolchain/parse/testdata/match/fail_missing_matched_expr.carbon
@@ -22,7 +22,7 @@ fn f() -> i32 {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'f'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'f'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
diff --git a/toolchain/parse/testdata/match/fail_unexpected_tokens_in_cases_block.carbon b/toolchain/parse/testdata/match/fail_unexpected_tokens_in_cases_block.carbon
index 57528b26f12b8..48092b57db80d 100644
--- a/toolchain/parse/testdata/match/fail_unexpected_tokens_in_cases_block.carbon
+++ b/toolchain/parse/testdata/match/fail_unexpected_tokens_in_cases_block.carbon
@@ -55,14 +55,14 @@ fn f() -> i32 {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'f'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'f'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'ReturnType', text: '->', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 7},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'VariableInitializer', text: '='},
@@ -74,7 +74,7 @@ fn f() -> i32 {
 // CHECK:STDOUT:           {kind: 'MatchCondition', text: ')', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'MatchStatementStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:             {kind: 'MatchCaseIntroducer', text: 'case'},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'y'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'y'},
 // CHECK:STDOUT:               {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:             {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:               {kind: 'MatchCaseGuardIntroducer', text: 'if'},
@@ -90,7 +90,7 @@ fn f() -> i32 {
 // CHECK:STDOUT:           {kind: 'ReturnStatement', text: ';', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'MatchCase', text: '}', subtree_size: 16},
 // CHECK:STDOUT:             {kind: 'MatchCaseIntroducer', text: 'case'},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'z'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'z'},
 // CHECK:STDOUT:               {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:             {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:               {kind: 'MatchCaseGuardIntroducer', text: 'if'},
diff --git a/toolchain/parse/testdata/match/match.carbon b/toolchain/parse/testdata/match/match.carbon
index c4755a9988ac4..591262f9311ee 100644
--- a/toolchain/parse/testdata/match/match.carbon
+++ b/toolchain/parse/testdata/match/match.carbon
@@ -23,14 +23,14 @@ fn f() -> i32 {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'f'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'f'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'ReturnType', text: '->', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 7},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'VariableInitializer', text: '='},
@@ -46,11 +46,11 @@ fn f() -> i32 {
 // CHECK:STDOUT:         {kind: 'MatchStatementStart', text: '{', subtree_size: 8},
 // CHECK:STDOUT:             {kind: 'MatchCaseIntroducer', text: 'case'},
 // CHECK:STDOUT:               {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:                 {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:                 {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:                 {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:               {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:               {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:                 {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:                 {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:                 {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:               {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:             {kind: 'TuplePattern', text: ')', subtree_size: 9},
@@ -62,7 +62,7 @@ fn f() -> i32 {
 // CHECK:STDOUT:         {kind: 'MatchCase', text: '}', subtree_size: 16},
 // CHECK:STDOUT:             {kind: 'MatchCaseIntroducer', text: 'case'},
 // CHECK:STDOUT:               {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:                 {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:                 {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:                 {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:               {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:             {kind: 'TuplePattern', text: ')', subtree_size: 5},
@@ -79,7 +79,7 @@ fn f() -> i32 {
 // CHECK:STDOUT:           {kind: 'ReturnStatement', text: ';', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'MatchCase', text: '}', subtree_size: 18},
 // CHECK:STDOUT:             {kind: 'MatchCaseIntroducer', text: 'case'},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:               {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:             {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:               {kind: 'MatchCaseGuardIntroducer', text: 'if'},
diff --git a/toolchain/parse/testdata/member_access/compound.carbon b/toolchain/parse/testdata/member_access/compound.carbon
index 7faef5bfcac5c..7f2d5a7cb0dba 100644
--- a/toolchain/parse/testdata/member_access/compound.carbon
+++ b/toolchain/parse/testdata/member_access/compound.carbon
@@ -17,7 +17,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/member_access/fail_keyword.carbon b/toolchain/parse/testdata/member_access/fail_keyword.carbon
index ae2302d8444b0..b63e202d603bb 100644
--- a/toolchain/parse/testdata/member_access/fail_keyword.carbon
+++ b/toolchain/parse/testdata/member_access/fail_keyword.carbon
@@ -44,32 +44,32 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:           {kind: 'IdentifierNameExpr', text: 'a'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'self', has_error: yes},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'self', has_error: yes},
 // CHECK:STDOUT:         {kind: 'MemberAccessExpr', text: '.', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ExprStatement', text: ';', subtree_size: 4},
 // CHECK:STDOUT:           {kind: 'IdentifierNameExpr', text: 'a'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'Self', has_error: yes},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'Self', has_error: yes},
 // CHECK:STDOUT:         {kind: 'MemberAccessExpr', text: '.', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ExprStatement', text: ';', subtree_size: 4},
 // CHECK:STDOUT:           {kind: 'IdentifierNameExpr', text: 'a'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'for', has_error: yes},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'for', has_error: yes},
 // CHECK:STDOUT:         {kind: 'MemberAccessExpr', text: '.', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ExprStatement', text: ';', subtree_size: 4},
 // CHECK:STDOUT:           {kind: 'IdentifierNameExpr', text: 'p'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'self', has_error: yes},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'self', has_error: yes},
 // CHECK:STDOUT:         {kind: 'PointerMemberAccessExpr', text: '->', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ExprStatement', text: ';', subtree_size: 4},
 // CHECK:STDOUT:           {kind: 'IdentifierNameExpr', text: 'p'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'Self', has_error: yes},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'Self', has_error: yes},
 // CHECK:STDOUT:         {kind: 'PointerMemberAccessExpr', text: '->', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ExprStatement', text: ';', subtree_size: 4},
 // CHECK:STDOUT:           {kind: 'IdentifierNameExpr', text: 'p'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'while', has_error: yes},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'while', has_error: yes},
 // CHECK:STDOUT:         {kind: 'PointerMemberAccessExpr', text: '->', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ExprStatement', text: ';', subtree_size: 4},
 // CHECK:STDOUT:     {kind: 'FunctionDefinition', text: '}', subtree_size: 30},
diff --git a/toolchain/parse/testdata/member_access/keyword.carbon b/toolchain/parse/testdata/member_access/keyword.carbon
index 6c80ed317c06d..913f95142e807 100644
--- a/toolchain/parse/testdata/member_access/keyword.carbon
+++ b/toolchain/parse/testdata/member_access/keyword.carbon
@@ -17,7 +17,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/member_access/simple.carbon b/toolchain/parse/testdata/member_access/simple.carbon
index 8c49e5453a02d..35b15fc780cc2 100644
--- a/toolchain/parse/testdata/member_access/simple.carbon
+++ b/toolchain/parse/testdata/member_access/simple.carbon
@@ -19,31 +19,31 @@ fn F(a: T) {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:             {kind: 'IdentifierNameExpr', text: 'T'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 5},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 8},
 // CHECK:STDOUT:           {kind: 'IdentifierNameExpr', text: 'a'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:         {kind: 'MemberAccessExpr', text: '.', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ExprStatement', text: ';', subtree_size: 4},
 // CHECK:STDOUT:           {kind: 'IdentifierNameExpr', text: 'a'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:         {kind: 'PointerMemberAccessExpr', text: '->', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ExprStatement', text: ';', subtree_size: 4},
 // CHECK:STDOUT:             {kind: 'IdentifierNameExpr', text: 'a'},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:           {kind: 'MemberAccessExpr', text: '.', subtree_size: 3},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'y'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'y'},
 // CHECK:STDOUT:         {kind: 'PointerMemberAccessExpr', text: '->', subtree_size: 5},
 // CHECK:STDOUT:       {kind: 'ExprStatement', text: ';', subtree_size: 6},
 // CHECK:STDOUT:             {kind: 'IdentifierNameExpr', text: 'a'},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:           {kind: 'PointerMemberAccessExpr', text: '->', subtree_size: 3},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'y'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'y'},
 // CHECK:STDOUT:         {kind: 'MemberAccessExpr', text: '.', subtree_size: 5},
 // CHECK:STDOUT:       {kind: 'ExprStatement', text: ';', subtree_size: 6},
 // CHECK:STDOUT:     {kind: 'FunctionDefinition', text: '}', subtree_size: 29},
diff --git a/toolchain/parse/testdata/namespace/args.carbon b/toolchain/parse/testdata/namespace/args.carbon
index 8d6f1032d0c5b..0572d9a65aa38 100644
--- a/toolchain/parse/testdata/namespace/args.carbon
+++ b/toolchain/parse/testdata/namespace/args.carbon
@@ -15,7 +15,7 @@ namespace Foo();
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'NamespaceStart', text: 'namespace'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'Namespace', text: ';', subtree_size: 5},
diff --git a/toolchain/parse/testdata/namespace/basic.carbon b/toolchain/parse/testdata/namespace/basic.carbon
index 874883c41a285..a61eee24e7e11 100644
--- a/toolchain/parse/testdata/namespace/basic.carbon
+++ b/toolchain/parse/testdata/namespace/basic.carbon
@@ -18,15 +18,15 @@ fn Bar() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'NamespaceStart', text: 'namespace'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:     {kind: 'Namespace', text: ';', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Bar'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'Bar'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:               {kind: 'IdentifierNameExpr', text: 'Foo'},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'Baz'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'Baz'},
 // CHECK:STDOUT:             {kind: 'MemberAccessExpr', text: '.', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'CallExprStart', text: '(', subtree_size: 4},
 // CHECK:STDOUT:         {kind: 'CallExpr', text: ')', subtree_size: 5},
diff --git a/toolchain/parse/testdata/namespace/fail_arrow.carbon b/toolchain/parse/testdata/namespace/fail_arrow.carbon
index 877a5fc3ce0b4..a3aff1f15877d 100644
--- a/toolchain/parse/testdata/namespace/fail_arrow.carbon
+++ b/toolchain/parse/testdata/namespace/fail_arrow.carbon
@@ -19,10 +19,10 @@ class Foo->Bar {}
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'NamespaceStart', text: 'namespace'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:     {kind: 'Namespace', text: ';', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:     {kind: 'ClassDecl', text: '}', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
 // CHECK:STDOUT:   ]
diff --git a/toolchain/parse/testdata/namespace/fail_incomplete_name.carbon b/toolchain/parse/testdata/namespace/fail_incomplete_name.carbon
index a4f9e4a9fc106..3452e3b829649 100644
--- a/toolchain/parse/testdata/namespace/fail_incomplete_name.carbon
+++ b/toolchain/parse/testdata/namespace/fail_incomplete_name.carbon
@@ -17,8 +17,8 @@ namespace Foo.;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'NamespaceStart', text: 'namespace'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Foo'},
-// CHECK:STDOUT:       {kind: 'NameQualifier', text: '.', subtree_size: 2},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'NameQualifierWithoutParams', text: '.', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'InvalidParse', text: ';', has_error: yes},
 // CHECK:STDOUT:     {kind: 'Namespace', text: ';', has_error: yes, subtree_size: 5},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
diff --git a/toolchain/parse/testdata/namespace/fail_modifiers.carbon b/toolchain/parse/testdata/namespace/fail_modifiers.carbon
index eeeb999838d47..bf98b7cbb16a9 100644
--- a/toolchain/parse/testdata/namespace/fail_modifiers.carbon
+++ b/toolchain/parse/testdata/namespace/fail_modifiers.carbon
@@ -24,7 +24,7 @@ impl namespace
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'NamespaceStart', text: 'namespace'},
 // CHECK:STDOUT:       {kind: 'VirtualModifier', text: 'virtual'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'B'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'B'},
 // CHECK:STDOUT:     {kind: 'Namespace', text: 'impl', has_error: yes, subtree_size: 4},
 // CHECK:STDOUT:       {kind: 'NamespaceStart', text: 'namespace'},
 // CHECK:STDOUT:       {kind: 'InvalidParse', text: '', has_error: yes},
diff --git a/toolchain/parse/testdata/namespace/local.carbon b/toolchain/parse/testdata/namespace/local.carbon
index 357d1345c1c92..60964f739a100 100644
--- a/toolchain/parse/testdata/namespace/local.carbon
+++ b/toolchain/parse/testdata/namespace/local.carbon
@@ -17,12 +17,12 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'NamespaceStart', text: 'namespace'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'N'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'N'},
 // CHECK:STDOUT:       {kind: 'Namespace', text: ';', subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'FunctionDefinition', text: '}', subtree_size: 9},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
diff --git a/toolchain/parse/testdata/namespace/modifiers.carbon b/toolchain/parse/testdata/namespace/modifiers.carbon
index 70961a18396a1..77f6d5613592f 100644
--- a/toolchain/parse/testdata/namespace/modifiers.carbon
+++ b/toolchain/parse/testdata/namespace/modifiers.carbon
@@ -22,11 +22,11 @@ impl namespace Foo;
 // CHECK:STDOUT:       {kind: 'BaseModifier', text: 'base'},
 // CHECK:STDOUT:       {kind: 'DefaultModifier', text: 'default'},
 // CHECK:STDOUT:       {kind: 'FinalModifier', text: 'final'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:     {kind: 'Namespace', text: ';', subtree_size: 9},
 // CHECK:STDOUT:       {kind: 'NamespaceStart', text: 'namespace'},
 // CHECK:STDOUT:       {kind: 'ImplModifier', text: 'impl'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:     {kind: 'Namespace', text: ';', subtree_size: 4},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
 // CHECK:STDOUT:   ]
diff --git a/toolchain/parse/testdata/namespace/nested.carbon b/toolchain/parse/testdata/namespace/nested.carbon
index 96070669f764a..ad896f56887df 100644
--- a/toolchain/parse/testdata/namespace/nested.carbon
+++ b/toolchain/parse/testdata/namespace/nested.carbon
@@ -19,26 +19,26 @@ fn Foo.Bar.Baz() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'NamespaceStart', text: 'namespace'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:     {kind: 'Namespace', text: ';', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'NamespaceStart', text: 'namespace'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Foo'},
-// CHECK:STDOUT:       {kind: 'NameQualifier', text: '.', subtree_size: 2},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Bar'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'NameQualifierWithoutParams', text: '.', subtree_size: 2},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'Bar'},
 // CHECK:STDOUT:     {kind: 'Namespace', text: ';', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'Foo'},
-// CHECK:STDOUT:         {kind: 'NameQualifier', text: '.', subtree_size: 2},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'Bar'},
-// CHECK:STDOUT:         {kind: 'NameQualifier', text: '.', subtree_size: 2},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Baz'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
+// CHECK:STDOUT:         {kind: 'NameQualifierWithoutParams', text: '.', subtree_size: 2},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'Bar'},
+// CHECK:STDOUT:         {kind: 'NameQualifierWithoutParams', text: '.', subtree_size: 2},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'Baz'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 9},
 // CHECK:STDOUT:                 {kind: 'IdentifierNameExpr', text: 'Foo'},
-// CHECK:STDOUT:                 {kind: 'IdentifierName', text: 'Bar'},
+// CHECK:STDOUT:                 {kind: 'IdentifierNameNotBeforeParams', text: 'Bar'},
 // CHECK:STDOUT:               {kind: 'MemberAccessExpr', text: '.', subtree_size: 3},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'Wiz'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'Wiz'},
 // CHECK:STDOUT:             {kind: 'MemberAccessExpr', text: '.', subtree_size: 5},
 // CHECK:STDOUT:           {kind: 'CallExprStart', text: '(', subtree_size: 6},
 // CHECK:STDOUT:         {kind: 'CallExpr', text: ')', subtree_size: 7},
diff --git a/toolchain/parse/testdata/operators/assign.carbon b/toolchain/parse/testdata/operators/assign.carbon
index 5e5714c1da643..9841a7ee641b3 100644
--- a/toolchain/parse/testdata/operators/assign.carbon
+++ b/toolchain/parse/testdata/operators/assign.carbon
@@ -30,19 +30,19 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'VariableInitializer', text: '='},
 // CHECK:STDOUT:         {kind: 'IntLiteral', text: '0'},
 // CHECK:STDOUT:       {kind: 'VariableDecl', text: ';', subtree_size: 7},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/operators/associative.carbon b/toolchain/parse/testdata/operators/associative.carbon
index f453fd78145c7..e35aeea1b47f7 100644
--- a/toolchain/parse/testdata/operators/associative.carbon
+++ b/toolchain/parse/testdata/operators/associative.carbon
@@ -16,7 +16,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/operators/fail_chained_assign.carbon b/toolchain/parse/testdata/operators/fail_chained_assign.carbon
index 779bab74b09b3..337c13bae94fd 100644
--- a/toolchain/parse/testdata/operators/fail_chained_assign.carbon
+++ b/toolchain/parse/testdata/operators/fail_chained_assign.carbon
@@ -23,17 +23,17 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableDecl', text: ';', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableDecl', text: ';', subtree_size: 5},
diff --git a/toolchain/parse/testdata/operators/fail_infix_uneven_space_after.carbon b/toolchain/parse/testdata/operators/fail_infix_uneven_space_after.carbon
index 8382387a1517e..5cb2b278ea2c7 100644
--- a/toolchain/parse/testdata/operators/fail_infix_uneven_space_after.carbon
+++ b/toolchain/parse/testdata/operators/fail_infix_uneven_space_after.carbon
@@ -19,7 +19,7 @@ var n: i8 = n* n;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i8'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/operators/fail_infix_uneven_space_before.carbon b/toolchain/parse/testdata/operators/fail_infix_uneven_space_before.carbon
index 9aff5d0719381..669bead76cf12 100644
--- a/toolchain/parse/testdata/operators/fail_infix_uneven_space_before.carbon
+++ b/toolchain/parse/testdata/operators/fail_infix_uneven_space_before.carbon
@@ -17,7 +17,7 @@ var n: i8 = n *n;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i8'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/operators/fail_invalid_infix.carbon b/toolchain/parse/testdata/operators/fail_invalid_infix.carbon
index 0b8b7953b4460..942eda0ed7c3f 100644
--- a/toolchain/parse/testdata/operators/fail_invalid_infix.carbon
+++ b/toolchain/parse/testdata/operators/fail_invalid_infix.carbon
@@ -31,7 +31,7 @@ var c: i32 = == ;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
@@ -40,7 +40,7 @@ var c: i32 = == ;
 // CHECK:STDOUT:       {kind: 'InfixOperatorEqualEqual', text: '==', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'VariableDecl', text: ';', subtree_size: 9},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
@@ -49,7 +49,7 @@ var c: i32 = == ;
 // CHECK:STDOUT:       {kind: 'InfixOperatorEqualEqual', text: '==', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'VariableDecl', text: ';', subtree_size: 9},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'c'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'c'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/operators/fail_postfix_space.carbon b/toolchain/parse/testdata/operators/fail_postfix_space.carbon
index 96a442c67dabd..71046080d7bd7 100644
--- a/toolchain/parse/testdata/operators/fail_postfix_space.carbon
+++ b/toolchain/parse/testdata/operators/fail_postfix_space.carbon
@@ -17,7 +17,7 @@ var v: type = i8 *;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'v'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'v'},
 // CHECK:STDOUT:         {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/operators/fail_postfix_space_before_comma.carbon b/toolchain/parse/testdata/operators/fail_postfix_space_before_comma.carbon
index 55b0c9e52d818..0308430466283 100644
--- a/toolchain/parse/testdata/operators/fail_postfix_space_before_comma.carbon
+++ b/toolchain/parse/testdata/operators/fail_postfix_space_before_comma.carbon
@@ -17,7 +17,7 @@ var n: i8 = F(i8 *, 0);
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i8'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/operators/fail_postfix_space_in_call.carbon b/toolchain/parse/testdata/operators/fail_postfix_space_in_call.carbon
index 92d49f8727644..5a7c5f92ca439 100644
--- a/toolchain/parse/testdata/operators/fail_postfix_space_in_call.carbon
+++ b/toolchain/parse/testdata/operators/fail_postfix_space_in_call.carbon
@@ -17,7 +17,7 @@ var n: i8 = F(i8 *);
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i8'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/operators/fail_postfix_space_surrounding.carbon b/toolchain/parse/testdata/operators/fail_postfix_space_surrounding.carbon
index a171015a32e8c..bc13043beac7b 100644
--- a/toolchain/parse/testdata/operators/fail_postfix_space_surrounding.carbon
+++ b/toolchain/parse/testdata/operators/fail_postfix_space_surrounding.carbon
@@ -17,7 +17,7 @@ var v: type = i8 * ;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'v'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'v'},
 // CHECK:STDOUT:         {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/operators/fail_postincrement.carbon b/toolchain/parse/testdata/operators/fail_postincrement.carbon
index 31f77bc7000c7..5875fe00c30f9 100644
--- a/toolchain/parse/testdata/operators/fail_postincrement.carbon
+++ b/toolchain/parse/testdata/operators/fail_postincrement.carbon
@@ -26,12 +26,12 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/operators/fail_precedence_and_or.carbon b/toolchain/parse/testdata/operators/fail_precedence_and_or.carbon
index e9417572e190e..2c4224797e4c4 100644
--- a/toolchain/parse/testdata/operators/fail_precedence_and_or.carbon
+++ b/toolchain/parse/testdata/operators/fail_precedence_and_or.carbon
@@ -19,7 +19,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/operators/fail_precedence_as.carbon b/toolchain/parse/testdata/operators/fail_precedence_as.carbon
index f9f093dc7c966..3abb252b912ea 100644
--- a/toolchain/parse/testdata/operators/fail_precedence_as.carbon
+++ b/toolchain/parse/testdata/operators/fail_precedence_as.carbon
@@ -56,9 +56,9 @@ fn F(n: i32) {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 5},
diff --git a/toolchain/parse/testdata/operators/fail_precedence_assign.carbon b/toolchain/parse/testdata/operators/fail_precedence_assign.carbon
index f60f43cd6a706..d73dd45b0995e 100644
--- a/toolchain/parse/testdata/operators/fail_precedence_assign.carbon
+++ b/toolchain/parse/testdata/operators/fail_precedence_assign.carbon
@@ -41,12 +41,12 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableDecl', text: ';', subtree_size: 5},
diff --git a/toolchain/parse/testdata/operators/fail_precedence_or_and.carbon b/toolchain/parse/testdata/operators/fail_precedence_or_and.carbon
index e83f504feee68..095319edadfc8 100644
--- a/toolchain/parse/testdata/operators/fail_precedence_or_and.carbon
+++ b/toolchain/parse/testdata/operators/fail_precedence_or_and.carbon
@@ -19,7 +19,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/operators/fail_precedence_where.carbon b/toolchain/parse/testdata/operators/fail_precedence_where.carbon
index 9afd40c150ea6..2afd400726881 100644
--- a/toolchain/parse/testdata/operators/fail_precedence_where.carbon
+++ b/toolchain/parse/testdata/operators/fail_precedence_where.carbon
@@ -101,7 +101,7 @@ fn GreaterInArgument() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'AndWhere'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'AndWhere'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
@@ -110,7 +110,7 @@ fn GreaterInArgument() {
 // CHECK:STDOUT:               {kind: 'IdentifierNameExpr', text: 'T'},
 // CHECK:STDOUT:             {kind: 'ShortCircuitOperatorAnd', text: 'and', subtree_size: 4},
 // CHECK:STDOUT:           {kind: 'WhereOperand', text: 'where', has_error: yes, subtree_size: 5},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'A'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'A'},
 // CHECK:STDOUT:             {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'IdentifierNameExpr', text: 'B'},
 // CHECK:STDOUT:           {kind: 'RequirementEqual', text: '=', subtree_size: 4},
@@ -123,13 +123,13 @@ fn GreaterInArgument() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'WhereOr'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'WhereOr'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:             {kind: 'IdentifierNameExpr', text: 'U'},
 // CHECK:STDOUT:           {kind: 'WhereOperand', text: 'where', subtree_size: 2},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'C'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'C'},
 // CHECK:STDOUT:             {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'IdentifierNameExpr', text: 'D'},
 // CHECK:STDOUT:           {kind: 'RequirementImpls', text: 'impls', subtree_size: 4},
@@ -142,7 +142,7 @@ fn GreaterInArgument() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'EqualsWhere'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'EqualsWhere'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
@@ -150,7 +150,7 @@ fn GreaterInArgument() {
 // CHECK:STDOUT:               {kind: 'IdentifierNameExpr', text: 'V'},
 // CHECK:STDOUT:             {kind: 'InfixOperatorEqualEqual', text: '==', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'WhereOperand', text: 'where', has_error: yes, subtree_size: 4},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'G'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'G'},
 // CHECK:STDOUT:             {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'FloatTypeLiteral', text: 'f32'},
 // CHECK:STDOUT:           {kind: 'RequirementEqualEqual', text: '==', subtree_size: 4},
@@ -163,13 +163,13 @@ fn GreaterInArgument() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'WhereNEq'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'WhereNEq'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:             {kind: 'IdentifierNameExpr', text: 'W'},
 // CHECK:STDOUT:           {kind: 'WhereOperand', text: 'where', subtree_size: 2},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'H'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'H'},
 // CHECK:STDOUT:             {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'BoolTypeLiteral', text: 'bool'},
 // CHECK:STDOUT:           {kind: 'RequirementEqual', text: '=', subtree_size: 4},
@@ -182,13 +182,13 @@ fn GreaterInArgument() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'LessRequirement'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'LessRequirement'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:             {kind: 'IdentifierNameExpr', text: 'X'},
 // CHECK:STDOUT:           {kind: 'WhereOperand', text: 'where', subtree_size: 2},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'J'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'J'},
 // CHECK:STDOUT:           {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
 // CHECK:STDOUT:         {kind: 'WhereExpr', text: 'where', has_error: yes, subtree_size: 5},
 // CHECK:STDOUT:       {kind: 'ExprStatement', text: ';', has_error: yes, subtree_size: 6},
@@ -199,7 +199,7 @@ fn GreaterInArgument() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'AsWhere'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'AsWhere'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
@@ -207,7 +207,7 @@ fn GreaterInArgument() {
 // CHECK:STDOUT:               {kind: 'IdentifierNameExpr', text: 'Z'},
 // CHECK:STDOUT:             {kind: 'InfixOperatorAs', text: 'as', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'WhereOperand', text: 'where', has_error: yes, subtree_size: 4},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'L'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'L'},
 // CHECK:STDOUT:             {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'IdentifierNameExpr', text: 'M'},
 // CHECK:STDOUT:           {kind: 'RequirementImpls', text: 'impls', subtree_size: 4},
@@ -220,13 +220,13 @@ fn GreaterInArgument() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'WhereAs'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'WhereAs'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:             {kind: 'IdentifierNameExpr', text: 'S'},
 // CHECK:STDOUT:           {kind: 'WhereOperand', text: 'where', subtree_size: 2},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'N'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'N'},
 // CHECK:STDOUT:             {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'RequirementEqualEqual', text: '==', subtree_size: 4},
@@ -239,13 +239,13 @@ fn GreaterInArgument() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'AsInArgument'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'AsInArgument'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:             {kind: 'IdentifierNameExpr', text: 'R'},
 // CHECK:STDOUT:           {kind: 'WhereOperand', text: 'where', subtree_size: 2},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'O'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'O'},
 // CHECK:STDOUT:           {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
 // CHECK:STDOUT:         {kind: 'WhereExpr', text: 'where', has_error: yes, subtree_size: 5},
 // CHECK:STDOUT:       {kind: 'ExprStatement', text: ';', has_error: yes, subtree_size: 6},
@@ -256,13 +256,13 @@ fn GreaterInArgument() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'GreaterInArgument'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'GreaterInArgument'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:             {kind: 'IdentifierNameExpr', text: 'Q'},
 // CHECK:STDOUT:           {kind: 'WhereOperand', text: 'where', subtree_size: 2},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'AA'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'AA'},
 // CHECK:STDOUT:           {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
 // CHECK:STDOUT:         {kind: 'WhereExpr', text: 'where', has_error: yes, subtree_size: 5},
 // CHECK:STDOUT:       {kind: 'ExprStatement', text: ';', has_error: yes, subtree_size: 6},
diff --git a/toolchain/parse/testdata/operators/fail_prefix_repeat.carbon b/toolchain/parse/testdata/operators/fail_prefix_repeat.carbon
index 64a2ab4346a8d..653dc79f3cbf1 100644
--- a/toolchain/parse/testdata/operators/fail_prefix_repeat.carbon
+++ b/toolchain/parse/testdata/operators/fail_prefix_repeat.carbon
@@ -18,7 +18,7 @@ fn F() -> const const i32* {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:                 {kind: 'IntTypeLiteral', text: 'i32'},
diff --git a/toolchain/parse/testdata/operators/fail_prefix_space.carbon b/toolchain/parse/testdata/operators/fail_prefix_space.carbon
index c3b9669dc9318..e3a0a5a67b085 100644
--- a/toolchain/parse/testdata/operators/fail_prefix_space.carbon
+++ b/toolchain/parse/testdata/operators/fail_prefix_space.carbon
@@ -17,7 +17,7 @@ var n: i8 = - n;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i8'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/operators/fail_prefix_uneven_space_with_assign.carbon b/toolchain/parse/testdata/operators/fail_prefix_uneven_space_with_assign.carbon
index 01d984e009822..7076c713174f0 100644
--- a/toolchain/parse/testdata/operators/fail_prefix_uneven_space_with_assign.carbon
+++ b/toolchain/parse/testdata/operators/fail_prefix_uneven_space_with_assign.carbon
@@ -17,7 +17,7 @@ var n: i8 =- n;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i8'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/operators/fail_star_minus.carbon b/toolchain/parse/testdata/operators/fail_star_minus.carbon
index a791c4d0f4106..86af91da378c9 100644
--- a/toolchain/parse/testdata/operators/fail_star_minus.carbon
+++ b/toolchain/parse/testdata/operators/fail_star_minus.carbon
@@ -22,7 +22,7 @@ var n: i8 = n* -n;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i8'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/operators/fail_star_star.carbon b/toolchain/parse/testdata/operators/fail_star_star.carbon
index 0175155ad67ac..1b63a5b51033c 100644
--- a/toolchain/parse/testdata/operators/fail_star_star.carbon
+++ b/toolchain/parse/testdata/operators/fail_star_star.carbon
@@ -17,7 +17,7 @@ var n: i8 = n* *p;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i8'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/operators/fail_star_star_no_space.carbon b/toolchain/parse/testdata/operators/fail_star_star_no_space.carbon
index fa2888a1342f6..38e4e3531249e 100644
--- a/toolchain/parse/testdata/operators/fail_star_star_no_space.carbon
+++ b/toolchain/parse/testdata/operators/fail_star_star_no_space.carbon
@@ -21,7 +21,7 @@ var n: i8 = n**p;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i8'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/operators/fail_variety.carbon b/toolchain/parse/testdata/operators/fail_variety.carbon
index 4e80172e27ac3..212fcdffc3c1c 100644
--- a/toolchain/parse/testdata/operators/fail_variety.carbon
+++ b/toolchain/parse/testdata/operators/fail_variety.carbon
@@ -35,7 +35,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/operators/fixity_in_call.carbon b/toolchain/parse/testdata/operators/fixity_in_call.carbon
index a1131c24b0256..b753d04dd7f47 100644
--- a/toolchain/parse/testdata/operators/fixity_in_call.carbon
+++ b/toolchain/parse/testdata/operators/fixity_in_call.carbon
@@ -16,7 +16,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/operators/fixity_in_params.carbon b/toolchain/parse/testdata/operators/fixity_in_params.carbon
index 78bf143b641bc..ff36507b3cc40 100644
--- a/toolchain/parse/testdata/operators/fixity_in_params.carbon
+++ b/toolchain/parse/testdata/operators/fixity_in_params.carbon
@@ -15,14 +15,14 @@ fn F(p: i32*, n: i32) {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'p'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'p'},
 // CHECK:STDOUT:               {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:             {kind: 'PostfixOperatorStar', text: '*', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 4},
 // CHECK:STDOUT:           {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 10},
diff --git a/toolchain/parse/testdata/operators/fixity_in_var.carbon b/toolchain/parse/testdata/operators/fixity_in_var.carbon
index e6bd1fa2016b1..884149856c40e 100644
--- a/toolchain/parse/testdata/operators/fixity_in_var.carbon
+++ b/toolchain/parse/testdata/operators/fixity_in_var.carbon
@@ -17,12 +17,12 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'q'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'q'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'PostfixOperatorStar', text: '*', subtree_size: 2},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 4},
@@ -30,7 +30,7 @@ fn F() {
 // CHECK:STDOUT:         {kind: 'IdentifierNameExpr', text: 'p'},
 // CHECK:STDOUT:       {kind: 'VariableDecl', text: ';', subtree_size: 8},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 't'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 't'},
 // CHECK:STDOUT:           {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/operators/fixity_with_assign.carbon b/toolchain/parse/testdata/operators/fixity_with_assign.carbon
index 9fa4856762df6..e685cee7d7bdf 100644
--- a/toolchain/parse/testdata/operators/fixity_with_assign.carbon
+++ b/toolchain/parse/testdata/operators/fixity_with_assign.carbon
@@ -19,7 +19,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/operators/infix.carbon b/toolchain/parse/testdata/operators/infix.carbon
index b4913514daf3c..972fcc8956cf3 100644
--- a/toolchain/parse/testdata/operators/infix.carbon
+++ b/toolchain/parse/testdata/operators/infix.carbon
@@ -20,7 +20,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/operators/infix_no_space.carbon b/toolchain/parse/testdata/operators/infix_no_space.carbon
index f836996f13f3a..91e321e885a95 100644
--- a/toolchain/parse/testdata/operators/infix_no_space.carbon
+++ b/toolchain/parse/testdata/operators/infix_no_space.carbon
@@ -14,7 +14,7 @@ var n: i8 = n*n;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i8'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/operators/infix_with_paren_after.carbon b/toolchain/parse/testdata/operators/infix_with_paren_after.carbon
index 14f8f37f278c9..1af63aa97c958 100644
--- a/toolchain/parse/testdata/operators/infix_with_paren_after.carbon
+++ b/toolchain/parse/testdata/operators/infix_with_paren_after.carbon
@@ -14,7 +14,7 @@ var n: i8 = 3*(n);
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i8'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/operators/infix_with_paren_before.carbon b/toolchain/parse/testdata/operators/infix_with_paren_before.carbon
index 18c5be200f72d..fbd162552bd40 100644
--- a/toolchain/parse/testdata/operators/infix_with_paren_before.carbon
+++ b/toolchain/parse/testdata/operators/infix_with_paren_before.carbon
@@ -14,7 +14,7 @@ var n: i8 = (n)*3;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i8'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/operators/postfix.carbon b/toolchain/parse/testdata/operators/postfix.carbon
index 0a28ef15f38af..25bf2d48d5979 100644
--- a/toolchain/parse/testdata/operators/postfix.carbon
+++ b/toolchain/parse/testdata/operators/postfix.carbon
@@ -14,7 +14,7 @@ var v: type = i8*;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'v'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'v'},
 // CHECK:STDOUT:         {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/operators/postfix_repeat.carbon b/toolchain/parse/testdata/operators/postfix_repeat.carbon
index 13bb0e9bf1bea..59e996bea6c0c 100644
--- a/toolchain/parse/testdata/operators/postfix_repeat.carbon
+++ b/toolchain/parse/testdata/operators/postfix_repeat.carbon
@@ -16,7 +16,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/operators/postfix_space_after_op.carbon b/toolchain/parse/testdata/operators/postfix_space_after_op.carbon
index 2a007bd3a413c..a28a9c08d1304 100644
--- a/toolchain/parse/testdata/operators/postfix_space_after_op.carbon
+++ b/toolchain/parse/testdata/operators/postfix_space_after_op.carbon
@@ -14,7 +14,7 @@ var v: type = i8* ;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'v'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'v'},
 // CHECK:STDOUT:         {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/operators/precedence_as.carbon b/toolchain/parse/testdata/operators/precedence_as.carbon
index b0861f2bd5ccf..71ee64fe40178 100644
--- a/toolchain/parse/testdata/operators/precedence_as.carbon
+++ b/toolchain/parse/testdata/operators/precedence_as.carbon
@@ -20,9 +20,9 @@ fn F(n: i32) {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 5},
diff --git a/toolchain/parse/testdata/operators/precedence_assign.carbon b/toolchain/parse/testdata/operators/precedence_assign.carbon
index a457975ab8135..560dd249cc729 100644
--- a/toolchain/parse/testdata/operators/precedence_assign.carbon
+++ b/toolchain/parse/testdata/operators/precedence_assign.carbon
@@ -21,25 +21,25 @@ fn F(c: bool) {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'c'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'c'},
 // CHECK:STDOUT:             {kind: 'BoolTypeLiteral', text: 'bool'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 5},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 8},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableDecl', text: ';', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableDecl', text: ';', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'p'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'p'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'PostfixOperatorStar', text: '*', subtree_size: 2},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 4},
diff --git a/toolchain/parse/testdata/operators/precedence_not.carbon b/toolchain/parse/testdata/operators/precedence_not.carbon
index 5abf41ef234f0..f730d6b604445 100644
--- a/toolchain/parse/testdata/operators/precedence_not.carbon
+++ b/toolchain/parse/testdata/operators/precedence_not.carbon
@@ -16,7 +16,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/operators/precedence_unary.carbon b/toolchain/parse/testdata/operators/precedence_unary.carbon
index 50686f2e8b8e0..af08610495cc4 100644
--- a/toolchain/parse/testdata/operators/precedence_unary.carbon
+++ b/toolchain/parse/testdata/operators/precedence_unary.carbon
@@ -21,9 +21,9 @@ fn F(p: i32*) {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'p'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'p'},
 // CHECK:STDOUT:               {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:             {kind: 'PostfixOperatorStar', text: '*', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 4},
diff --git a/toolchain/parse/testdata/operators/precedence_where.carbon b/toolchain/parse/testdata/operators/precedence_where.carbon
index 6c160b3f6d054..67dc431ee8da4 100644
--- a/toolchain/parse/testdata/operators/precedence_where.carbon
+++ b/toolchain/parse/testdata/operators/precedence_where.carbon
@@ -20,16 +20,16 @@ fn UnaryMinus(W:! -P where -Q impls -R);
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'PostfixStar'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'PostfixStar'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'T'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'T'},
 // CHECK:STDOUT:                 {kind: 'IdentifierNameExpr', text: 'I'},
 // CHECK:STDOUT:               {kind: 'PostfixOperatorStar', text: '*', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'WhereOperand', text: 'where', subtree_size: 3},
-// CHECK:STDOUT:                   {kind: 'IdentifierName', text: 'A'},
+// CHECK:STDOUT:                   {kind: 'IdentifierNameNotBeforeParams', text: 'A'},
 // CHECK:STDOUT:                 {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
 // CHECK:STDOUT:               {kind: 'PostfixOperatorStar', text: '*', subtree_size: 3},
-// CHECK:STDOUT:                   {kind: 'IdentifierName', text: 'B'},
+// CHECK:STDOUT:                   {kind: 'IdentifierNameNotBeforeParams', text: 'B'},
 // CHECK:STDOUT:                 {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
 // CHECK:STDOUT:               {kind: 'PostfixOperatorStar', text: '*', subtree_size: 3},
 // CHECK:STDOUT:             {kind: 'RequirementEqualEqual', text: '==', subtree_size: 7},
@@ -38,9 +38,9 @@ fn UnaryMinus(W:! -P where -Q impls -R);
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 15},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ';', subtree_size: 18},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Ampersand'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'Ampersand'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'U'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'U'},
 // CHECK:STDOUT:                 {kind: 'IdentifierNameExpr', text: 'J'},
 // CHECK:STDOUT:                 {kind: 'IdentifierNameExpr', text: 'K'},
 // CHECK:STDOUT:               {kind: 'InfixOperatorAmp', text: '&', subtree_size: 3},
@@ -57,9 +57,9 @@ fn UnaryMinus(W:! -P where -Q impls -R);
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 16},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ';', subtree_size: 19},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'BinaryPlus'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'BinaryPlus'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'V'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'V'},
 // CHECK:STDOUT:                 {kind: 'IdentifierNameExpr', text: 'L'},
 // CHECK:STDOUT:                 {kind: 'IdentifierNameExpr', text: 'M'},
 // CHECK:STDOUT:               {kind: 'InfixOperatorPlus', text: '+', subtree_size: 3},
@@ -76,9 +76,9 @@ fn UnaryMinus(W:! -P where -Q impls -R);
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 16},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ';', subtree_size: 19},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'UnaryMinus'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'UnaryMinus'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'W'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'W'},
 // CHECK:STDOUT:                 {kind: 'IdentifierNameExpr', text: 'P'},
 // CHECK:STDOUT:               {kind: 'PrefixOperatorMinus', text: '-', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'WhereOperand', text: 'where', subtree_size: 3},
diff --git a/toolchain/parse/testdata/operators/prefix.carbon b/toolchain/parse/testdata/operators/prefix.carbon
index f86a3d8c0a4b8..2646d541af8aa 100644
--- a/toolchain/parse/testdata/operators/prefix.carbon
+++ b/toolchain/parse/testdata/operators/prefix.carbon
@@ -15,7 +15,7 @@ var b: bool = not true;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i8'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
@@ -23,7 +23,7 @@ var b: bool = not true;
 // CHECK:STDOUT:       {kind: 'PrefixOperatorMinus', text: '-', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'VariableDecl', text: ';', subtree_size: 8},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:         {kind: 'BoolTypeLiteral', text: 'bool'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/operators/prefix_no_space.carbon b/toolchain/parse/testdata/operators/prefix_no_space.carbon
index eb6dca7ab8675..989230bb3bbff 100644
--- a/toolchain/parse/testdata/operators/prefix_no_space.carbon
+++ b/toolchain/parse/testdata/operators/prefix_no_space.carbon
@@ -15,7 +15,7 @@ var n: i8 =-n;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i8'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/operators/prefix_repeat.carbon b/toolchain/parse/testdata/operators/prefix_repeat.carbon
index b000c075e7e66..c58cdd9fcc842 100644
--- a/toolchain/parse/testdata/operators/prefix_repeat.carbon
+++ b/toolchain/parse/testdata/operators/prefix_repeat.carbon
@@ -16,7 +16,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/operators/spaceship.carbon b/toolchain/parse/testdata/operators/spaceship.carbon
index f8446db229103..622f17c653ccf 100644
--- a/toolchain/parse/testdata/operators/spaceship.carbon
+++ b/toolchain/parse/testdata/operators/spaceship.carbon
@@ -16,7 +16,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/operators/three_stars.carbon b/toolchain/parse/testdata/operators/three_stars.carbon
index 32d3ae98db204..43457e8da45a4 100644
--- a/toolchain/parse/testdata/operators/three_stars.carbon
+++ b/toolchain/parse/testdata/operators/three_stars.carbon
@@ -16,7 +16,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/operators/unary.carbon b/toolchain/parse/testdata/operators/unary.carbon
index cf6ba2a384c62..1afc41ecab723 100644
--- a/toolchain/parse/testdata/operators/unary.carbon
+++ b/toolchain/parse/testdata/operators/unary.carbon
@@ -27,7 +27,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
@@ -47,7 +47,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/package_expr/basic.carbon b/toolchain/parse/testdata/package_expr/basic.carbon
index 487b5d813ff3b..8d3213adc3359 100644
--- a/toolchain/parse/testdata/package_expr/basic.carbon
+++ b/toolchain/parse/testdata/package_expr/basic.carbon
@@ -14,14 +14,14 @@ var x: package.Foo = package.Bar;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:           {kind: 'PackageExpr', text: 'package'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:         {kind: 'MemberAccessExpr', text: '.', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 5},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
 // CHECK:STDOUT:         {kind: 'PackageExpr', text: 'package'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Bar'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'Bar'},
 // CHECK:STDOUT:       {kind: 'MemberAccessExpr', text: '.', subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'VariableDecl', text: ';', subtree_size: 11},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
diff --git a/toolchain/parse/testdata/package_expr/fail_in_name.carbon b/toolchain/parse/testdata/package_expr/fail_in_name.carbon
index b849a75b96957..4de8e64d94821 100644
--- a/toolchain/parse/testdata/package_expr/fail_in_name.carbon
+++ b/toolchain/parse/testdata/package_expr/fail_in_name.carbon
@@ -30,7 +30,7 @@ class package.C {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'package', has_error: yes},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'package', has_error: yes},
 // CHECK:STDOUT:         {kind: 'InvalidParse', text: 'package', has_error: yes},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: 'package', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'VariableDecl', text: ';', subtree_size: 5},
diff --git a/toolchain/parse/testdata/package_expr/fail_standalone.carbon b/toolchain/parse/testdata/package_expr/fail_standalone.carbon
index 2995863efd641..7fc2de7ed539a 100644
--- a/toolchain/parse/testdata/package_expr/fail_standalone.carbon
+++ b/toolchain/parse/testdata/package_expr/fail_standalone.carbon
@@ -19,7 +19,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/packages/export.carbon b/toolchain/parse/testdata/packages/export.carbon
index 180dfc74508dc..5eb16eb8f4fe7 100644
--- a/toolchain/parse/testdata/packages/export.carbon
+++ b/toolchain/parse/testdata/packages/export.carbon
@@ -149,7 +149,7 @@ export Foo;
 // CHECK:STDOUT:       {kind: 'PackageName', text: 'Pkg'},
 // CHECK:STDOUT:     {kind: 'PackageDecl', text: ';', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ExportIntroducer', text: 'export'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:     {kind: 'ExportDecl', text: ';', subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
 // CHECK:STDOUT:   ]
@@ -160,9 +160,9 @@ export Foo;
 // CHECK:STDOUT:       {kind: 'PackageName', text: 'Pkg'},
 // CHECK:STDOUT:     {kind: 'PackageDecl', text: ';', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ExportIntroducer', text: 'export'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Foo'},
-// CHECK:STDOUT:       {kind: 'NameQualifier', text: '.', subtree_size: 2},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Bar'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'NameQualifierWithoutParams', text: '.', subtree_size: 2},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'Bar'},
 // CHECK:STDOUT:     {kind: 'ExportDecl', text: ';', subtree_size: 5},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
 // CHECK:STDOUT:   ]
@@ -217,7 +217,7 @@ export Foo;
 // CHECK:STDOUT:       {kind: 'PackageName', text: 'Pkg'},
 // CHECK:STDOUT:     {kind: 'PackageDecl', text: ';', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ExportIntroducer', text: 'export'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:     {kind: 'ExportDecl', text: 'Foo', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
 // CHECK:STDOUT:   ]
@@ -228,8 +228,8 @@ export Foo;
 // CHECK:STDOUT:       {kind: 'PackageName', text: 'Pkg'},
 // CHECK:STDOUT:     {kind: 'PackageDecl', text: ';', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ExportIntroducer', text: 'export'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Foo'},
-// CHECK:STDOUT:       {kind: 'NameQualifier', text: '.', subtree_size: 2},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'NameQualifierWithoutParams', text: '.', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'InvalidParse', text: ';', has_error: yes},
 // CHECK:STDOUT:     {kind: 'ExportDecl', text: ';', has_error: yes, subtree_size: 5},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
@@ -252,10 +252,10 @@ export Foo;
 // CHECK:STDOUT:       {kind: 'PackageName', text: 'Pkg'},
 // CHECK:STDOUT:     {kind: 'PackageDecl', text: ';', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'C'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'C'},
 // CHECK:STDOUT:     {kind: 'ClassDecl', text: ';', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ExportIntroducer', text: 'export'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:     {kind: 'ExportDecl', text: ';', subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
 // CHECK:STDOUT:   ]
@@ -266,7 +266,7 @@ export Foo;
 // CHECK:STDOUT:       {kind: 'PackageName', text: 'Pkg'},
 // CHECK:STDOUT:     {kind: 'PackageDecl', text: ';', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ExportIntroducer', text: 'export'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:     {kind: 'ExportDecl', text: ';', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ImportIntroducer', text: 'import'},
 // CHECK:STDOUT:     {kind: 'ImportDecl', text: ';', has_error: yes, subtree_size: 2},
@@ -276,7 +276,7 @@ export Foo;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'ExportIntroducer', text: 'export'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:     {kind: 'ExportDecl', text: ';', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
 // CHECK:STDOUT:   ]
@@ -288,7 +288,7 @@ export Foo;
 // CHECK:STDOUT:       {kind: 'PackageName', text: 'Pkg'},
 // CHECK:STDOUT:     {kind: 'PackageDecl', text: ';', subtree_size: 4},
 // CHECK:STDOUT:       {kind: 'ExportIntroducer', text: 'export'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:     {kind: 'ExportDecl', text: ';', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'FileEnd', text: ''},
 // CHECK:STDOUT:   ]
diff --git a/toolchain/parse/testdata/packages/import/export.carbon b/toolchain/parse/testdata/packages/import/export.carbon
index f8db17dd37bf3..e06a226d7b0ea 100644
--- a/toolchain/parse/testdata/packages/import/export.carbon
+++ b/toolchain/parse/testdata/packages/import/export.carbon
@@ -114,7 +114,7 @@ export import library "lib";
 // CHECK:STDOUT:       {kind: 'LibrarySpecifier', text: 'library', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'ImportDecl', text: ';', subtree_size: 5},
 // CHECK:STDOUT:       {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'C'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameNotBeforeParams', text: 'C'},
 // CHECK:STDOUT:     {kind: 'ClassDecl', text: ';', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ImportIntroducer', text: 'import'},
 // CHECK:STDOUT:       {kind: 'ExportModifier', text: 'export'},
diff --git a/toolchain/parse/testdata/packages/import/fail_after_decl.carbon b/toolchain/parse/testdata/packages/import/fail_after_decl.carbon
index 0277cfc4ee769..76ca7e85a8ee9 100644
--- a/toolchain/parse/testdata/packages/import/fail_after_decl.carbon
+++ b/toolchain/parse/testdata/packages/import/fail_after_decl.carbon
@@ -22,7 +22,7 @@ import B;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'A'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'A'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ';', subtree_size: 5},
diff --git a/toolchain/parse/testdata/packages/import/fail_after_decl_repeated.carbon b/toolchain/parse/testdata/packages/import/fail_after_decl_repeated.carbon
index bb9f3b5297802..f531f0539f2dd 100644
--- a/toolchain/parse/testdata/packages/import/fail_after_decl_repeated.carbon
+++ b/toolchain/parse/testdata/packages/import/fail_after_decl_repeated.carbon
@@ -46,7 +46,7 @@ import G;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'A'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'A'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ';', subtree_size: 5},
@@ -57,7 +57,7 @@ import G;
 // CHECK:STDOUT:       {kind: 'PackageIntroducer', text: 'package'},
 // CHECK:STDOUT:     {kind: 'PackageDecl', text: ';', has_error: yes, subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'E'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'E'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ';', subtree_size: 5},
diff --git a/toolchain/parse/testdata/packages/import/fail_in_nested_scope.carbon b/toolchain/parse/testdata/packages/import/fail_in_nested_scope.carbon
index 98b469ae3e0df..a7900c1bc8616 100644
--- a/toolchain/parse/testdata/packages/import/fail_in_nested_scope.carbon
+++ b/toolchain/parse/testdata/packages/import/fail_in_nested_scope.carbon
@@ -33,13 +33,13 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'A'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'A'},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'ImportIntroducer', text: 'import'},
 // CHECK:STDOUT:       {kind: 'ImportDecl', text: ';', has_error: yes, subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'ClassDefinition', text: '}', subtree_size: 6},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/packages/library/fail_in_nested_scope.carbon b/toolchain/parse/testdata/packages/library/fail_in_nested_scope.carbon
index 2c6395d389510..927130f4953a6 100644
--- a/toolchain/parse/testdata/packages/library/fail_in_nested_scope.carbon
+++ b/toolchain/parse/testdata/packages/library/fail_in_nested_scope.carbon
@@ -59,13 +59,13 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'C'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'C'},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'LibraryIntroducer', text: 'library'},
 // CHECK:STDOUT:       {kind: 'LibraryDecl', text: ';', has_error: yes, subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'ClassDefinition', text: '}', subtree_size: 6},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
@@ -73,14 +73,14 @@ fn F() {
 // CHECK:STDOUT:       {kind: 'LibraryDecl', text: ';', has_error: yes, subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'FunctionDefinition', text: '}', subtree_size: 8},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'C'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'C'},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'LibraryIntroducer', text: 'library'},
 // CHECK:STDOUT:         {kind: 'ImplModifier', text: 'impl'},
 // CHECK:STDOUT:       {kind: 'LibraryDecl', text: ';', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'ClassDefinition', text: '}', subtree_size: 7},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/packages/package/fail_after_decl.carbon b/toolchain/parse/testdata/packages/package/fail_after_decl.carbon
index 6d8410ea98ee9..a87c4eeff66aa 100644
--- a/toolchain/parse/testdata/packages/package/fail_after_decl.carbon
+++ b/toolchain/parse/testdata/packages/package/fail_after_decl.carbon
@@ -22,7 +22,7 @@ package B;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'A'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'A'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ';', subtree_size: 5},
diff --git a/toolchain/parse/testdata/packages/package/fail_in_nested_scope.carbon b/toolchain/parse/testdata/packages/package/fail_in_nested_scope.carbon
index fca605ee2dc08..0652a435e58de 100644
--- a/toolchain/parse/testdata/packages/package/fail_in_nested_scope.carbon
+++ b/toolchain/parse/testdata/packages/package/fail_in_nested_scope.carbon
@@ -61,32 +61,32 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'C'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'C'},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'PackageIntroducer', text: 'package'},
 // CHECK:STDOUT:       {kind: 'PackageDecl', text: ';', has_error: yes, subtree_size: 2},
 // CHECK:STDOUT:     {kind: 'ClassDefinition', text: '}', subtree_size: 6},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'PackageExpr', text: 'package'},
 // CHECK:STDOUT:       {kind: 'ExprStatement', text: ';', has_error: yes, subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'PackageExpr', text: 'package'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'P'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'P'},
 // CHECK:STDOUT:         {kind: 'MemberAccessExpr', text: '.', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ExprStatement', text: ';', subtree_size: 4},
 // CHECK:STDOUT:     {kind: 'FunctionDefinition', text: '}', subtree_size: 12},
 // CHECK:STDOUT:         {kind: 'ClassIntroducer', text: 'class'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'C'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'C'},
 // CHECK:STDOUT:       {kind: 'ClassDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'PackageIntroducer', text: 'package'},
 // CHECK:STDOUT:         {kind: 'ImplModifier', text: 'impl'},
 // CHECK:STDOUT:       {kind: 'PackageDecl', text: ';', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'ClassDefinition', text: '}', subtree_size: 7},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/packages/package/impl.carbon b/toolchain/parse/testdata/packages/package/impl.carbon
index 322b14f5f6aeb..00b3d6dcd5b34 100644
--- a/toolchain/parse/testdata/packages/package/impl.carbon
+++ b/toolchain/parse/testdata/packages/package/impl.carbon
@@ -57,11 +57,11 @@ impl package.Name as package.Interface {}
 // CHECK:STDOUT:     {kind: 'PackageDecl', text: ';', subtree_size: 4},
 // CHECK:STDOUT:         {kind: 'ImplIntroducer', text: 'impl'},
 // CHECK:STDOUT:             {kind: 'PackageExpr', text: 'package'},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'Name'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'Name'},
 // CHECK:STDOUT:           {kind: 'MemberAccessExpr', text: '.', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TypeImplAs', text: 'as', subtree_size: 4},
 // CHECK:STDOUT:           {kind: 'PackageExpr', text: 'package'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'Interface'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'Interface'},
 // CHECK:STDOUT:         {kind: 'MemberAccessExpr', text: '.', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'ImplDefinitionStart', text: '{', subtree_size: 9},
 // CHECK:STDOUT:     {kind: 'ImplDefinition', text: '}', subtree_size: 10},
diff --git a/toolchain/parse/testdata/pointer/const_pointer.carbon b/toolchain/parse/testdata/pointer/const_pointer.carbon
index e301ef5623895..80b9b7fedbbaf 100644
--- a/toolchain/parse/testdata/pointer/const_pointer.carbon
+++ b/toolchain/parse/testdata/pointer/const_pointer.carbon
@@ -16,7 +16,7 @@ fn C() -> const (i32*) { return C(); }
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'A'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'A'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:               {kind: 'IntTypeLiteral', text: 'i32'},
@@ -31,7 +31,7 @@ fn C() -> const (i32*) { return C(); }
 // CHECK:STDOUT:       {kind: 'ReturnStatement', text: ';', subtree_size: 5},
 // CHECK:STDOUT:     {kind: 'FunctionDefinition', text: '}', subtree_size: 15},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'B'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'B'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:               {kind: 'ParenExprStart', text: '('},
@@ -48,7 +48,7 @@ fn C() -> const (i32*) { return C(); }
 // CHECK:STDOUT:       {kind: 'ReturnStatement', text: ';', subtree_size: 5},
 // CHECK:STDOUT:     {kind: 'FunctionDefinition', text: '}', subtree_size: 17},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'C'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'C'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:               {kind: 'ParenExprStart', text: '('},
diff --git a/toolchain/parse/testdata/pointer/fail_pointer_type_in_expr.carbon b/toolchain/parse/testdata/pointer/fail_pointer_type_in_expr.carbon
index 7f0bc82ccf163..ad3b49d9ca3a9 100644
--- a/toolchain/parse/testdata/pointer/fail_pointer_type_in_expr.carbon
+++ b/toolchain/parse/testdata/pointer/fail_pointer_type_in_expr.carbon
@@ -19,7 +19,7 @@ fn F() -> i32 {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
diff --git a/toolchain/parse/testdata/pointer/fail_tuple_instead_of_compound_member_access.carbon b/toolchain/parse/testdata/pointer/fail_tuple_instead_of_compound_member_access.carbon
index 118d1a2a3b23c..02de2fea28350 100644
--- a/toolchain/parse/testdata/pointer/fail_tuple_instead_of_compound_member_access.carbon
+++ b/toolchain/parse/testdata/pointer/fail_tuple_instead_of_compound_member_access.carbon
@@ -61,7 +61,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/pointer/pointer_type.carbon b/toolchain/parse/testdata/pointer/pointer_type.carbon
index 51579b0ba591d..2a470ab9787be 100644
--- a/toolchain/parse/testdata/pointer/pointer_type.carbon
+++ b/toolchain/parse/testdata/pointer/pointer_type.carbon
@@ -20,9 +20,9 @@ var T: type = if true then i32* else f64*;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'p'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'p'},
 // CHECK:STDOUT:               {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:             {kind: 'PostfixOperatorStar', text: '*', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 4},
@@ -54,7 +54,7 @@ var T: type = if true then i32* else f64*;
 // CHECK:STDOUT:       {kind: 'ReturnStatement', text: ';', subtree_size: 9},
 // CHECK:STDOUT:     {kind: 'FunctionDefinition', text: '}', subtree_size: 34},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'T'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'T'},
 // CHECK:STDOUT:         {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/pointer/pointer_value.carbon b/toolchain/parse/testdata/pointer/pointer_value.carbon
index 67881dbe87708..3c5ffc3ee9871 100644
--- a/toolchain/parse/testdata/pointer/pointer_value.carbon
+++ b/toolchain/parse/testdata/pointer/pointer_value.carbon
@@ -19,21 +19,21 @@ fn F() -> i32 {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'ReturnType', text: '->', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 7},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'VariableInitializer', text: '='},
 // CHECK:STDOUT:         {kind: 'IntLiteral', text: '0'},
 // CHECK:STDOUT:       {kind: 'VariableDecl', text: ';', subtree_size: 7},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'p'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'p'},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'PostfixOperatorStar', text: '*', subtree_size: 2},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 4},
@@ -42,7 +42,7 @@ fn F() -> i32 {
 // CHECK:STDOUT:         {kind: 'PrefixOperatorAmp', text: '&', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'VariableDecl', text: ';', subtree_size: 9},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'q'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'q'},
 // CHECK:STDOUT:               {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:             {kind: 'PostfixOperatorStar', text: '*', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'PostfixOperatorStar', text: '*', subtree_size: 3},
diff --git a/toolchain/parse/testdata/return/basic.carbon b/toolchain/parse/testdata/return/basic.carbon
index d8801da29c582..bc1c57c9f12e1 100644
--- a/toolchain/parse/testdata/return/basic.carbon
+++ b/toolchain/parse/testdata/return/basic.carbon
@@ -16,7 +16,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/return/expr.carbon b/toolchain/parse/testdata/return/expr.carbon
index f14981bef1594..30e3a404e7661 100644
--- a/toolchain/parse/testdata/return/expr.carbon
+++ b/toolchain/parse/testdata/return/expr.carbon
@@ -16,7 +16,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/return/fail_expr_no_semi.carbon b/toolchain/parse/testdata/return/fail_expr_no_semi.carbon
index 9a1be88d9b1e7..ebd9d229dbe20 100644
--- a/toolchain/parse/testdata/return/fail_expr_no_semi.carbon
+++ b/toolchain/parse/testdata/return/fail_expr_no_semi.carbon
@@ -19,7 +19,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/return/fail_no_semi.carbon b/toolchain/parse/testdata/return/fail_no_semi.carbon
index c1a4c03aa37b8..2b1c3f03143fa 100644
--- a/toolchain/parse/testdata/return/fail_no_semi.carbon
+++ b/toolchain/parse/testdata/return/fail_no_semi.carbon
@@ -23,7 +23,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/return/fail_returned_no_var.carbon b/toolchain/parse/testdata/return/fail_returned_no_var.carbon
index 18d1495e5694e..fbbf4dee5361b 100644
--- a/toolchain/parse/testdata/return/fail_returned_no_var.carbon
+++ b/toolchain/parse/testdata/return/fail_returned_no_var.carbon
@@ -19,7 +19,7 @@ fn F() -> String {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'StringTypeLiteral', text: 'String'},
diff --git a/toolchain/parse/testdata/return/fail_var_no_semi.carbon b/toolchain/parse/testdata/return/fail_var_no_semi.carbon
index 36f06d90164e4..e6cc5d4c5bb61 100644
--- a/toolchain/parse/testdata/return/fail_var_no_semi.carbon
+++ b/toolchain/parse/testdata/return/fail_var_no_semi.carbon
@@ -19,7 +19,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/return/returned_var.carbon b/toolchain/parse/testdata/return/returned_var.carbon
index 13fe41894de9c..cd912fc8e4958 100644
--- a/toolchain/parse/testdata/return/returned_var.carbon
+++ b/toolchain/parse/testdata/return/returned_var.carbon
@@ -17,7 +17,7 @@ fn F() -> String {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'StringTypeLiteral', text: 'String'},
@@ -25,7 +25,7 @@ fn F() -> String {
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 7},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
 // CHECK:STDOUT:         {kind: 'ReturnedModifier', text: 'returned'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 's'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 's'},
 // CHECK:STDOUT:           {kind: 'StringTypeLiteral', text: 'String'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/struct/fail_comma_only.carbon b/toolchain/parse/testdata/struct/fail_comma_only.carbon
index 06cd25e6a0898..85dd0e3994eba 100644
--- a/toolchain/parse/testdata/struct/fail_comma_only.carbon
+++ b/toolchain/parse/testdata/struct/fail_comma_only.carbon
@@ -17,7 +17,7 @@ var x: {,} = {};
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:           {kind: 'StructLiteralStart', text: '{'},
 // CHECK:STDOUT:           {kind: 'InvalidParse', text: ',', has_error: yes},
 // CHECK:STDOUT:           {kind: 'InvalidParse', text: ',', has_error: yes},
diff --git a/toolchain/parse/testdata/struct/fail_comma_repeat_in_type.carbon b/toolchain/parse/testdata/struct/fail_comma_repeat_in_type.carbon
index cea1e9bc5dd92..2ee4ff188883b 100644
--- a/toolchain/parse/testdata/struct/fail_comma_repeat_in_type.carbon
+++ b/toolchain/parse/testdata/struct/fail_comma_repeat_in_type.carbon
@@ -17,9 +17,9 @@ var x: {.a: i32,,} = {};
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:           {kind: 'StructTypeLiteralStart', text: '{'},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:             {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'StructTypeLiteralField', text: ':', subtree_size: 4},
diff --git a/toolchain/parse/testdata/struct/fail_comma_repeat_in_value.carbon b/toolchain/parse/testdata/struct/fail_comma_repeat_in_value.carbon
index d689fb301a8cf..1430ef5aea1f6 100644
--- a/toolchain/parse/testdata/struct/fail_comma_repeat_in_value.carbon
+++ b/toolchain/parse/testdata/struct/fail_comma_repeat_in_value.carbon
@@ -17,9 +17,9 @@ var x: {.a = 0,,} = {};
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:           {kind: 'StructLiteralStart', text: '{'},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:             {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'IntLiteral', text: '0'},
 // CHECK:STDOUT:           {kind: 'StructLiteralField', text: '=', subtree_size: 4},
diff --git a/toolchain/parse/testdata/struct/fail_extra_token_in_type.carbon b/toolchain/parse/testdata/struct/fail_extra_token_in_type.carbon
index de396645218ef..4411a25796f5e 100644
--- a/toolchain/parse/testdata/struct/fail_extra_token_in_type.carbon
+++ b/toolchain/parse/testdata/struct/fail_extra_token_in_type.carbon
@@ -17,9 +17,9 @@ var x: {.a: i32 banana} = {.a = 0};
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:           {kind: 'StructTypeLiteralStart', text: '{'},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:             {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'StructTypeLiteralField', text: ':', subtree_size: 4},
@@ -27,7 +27,7 @@ var x: {.a: i32 banana} = {.a = 0};
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 8},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
 // CHECK:STDOUT:         {kind: 'StructLiteralStart', text: '{'},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:           {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'IntLiteral', text: '0'},
 // CHECK:STDOUT:         {kind: 'StructLiteralField', text: '=', subtree_size: 4},
diff --git a/toolchain/parse/testdata/struct/fail_extra_token_in_value.carbon b/toolchain/parse/testdata/struct/fail_extra_token_in_value.carbon
index f53bf5a971304..79dbd3aa0f681 100644
--- a/toolchain/parse/testdata/struct/fail_extra_token_in_value.carbon
+++ b/toolchain/parse/testdata/struct/fail_extra_token_in_value.carbon
@@ -17,9 +17,9 @@ var x: {.a: i32} = {.a = 0 banana};
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:           {kind: 'StructTypeLiteralStart', text: '{'},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:             {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'StructTypeLiteralField', text: ':', subtree_size: 4},
@@ -27,7 +27,7 @@ var x: {.a: i32} = {.a = 0 banana};
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 8},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
 // CHECK:STDOUT:         {kind: 'StructLiteralStart', text: '{'},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:           {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'IntLiteral', text: '0'},
 // CHECK:STDOUT:         {kind: 'StructLiteralField', text: '=', subtree_size: 4},
diff --git a/toolchain/parse/testdata/struct/fail_identifier_colon.carbon b/toolchain/parse/testdata/struct/fail_identifier_colon.carbon
index 414ed37194914..0bab495e6808d 100644
--- a/toolchain/parse/testdata/struct/fail_identifier_colon.carbon
+++ b/toolchain/parse/testdata/struct/fail_identifier_colon.carbon
@@ -17,7 +17,7 @@ var x: {a:} = {};
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:           {kind: 'StructLiteralStart', text: '{'},
 // CHECK:STDOUT:           {kind: 'InvalidParse', text: 'a', has_error: yes},
 // CHECK:STDOUT:         {kind: 'StructLiteral', text: '}', has_error: yes, subtree_size: 3},
diff --git a/toolchain/parse/testdata/struct/fail_identifier_equals.carbon b/toolchain/parse/testdata/struct/fail_identifier_equals.carbon
index d96d9a5c1a064..6394a90f2becb 100644
--- a/toolchain/parse/testdata/struct/fail_identifier_equals.carbon
+++ b/toolchain/parse/testdata/struct/fail_identifier_equals.carbon
@@ -17,7 +17,7 @@ var x: {a=} = {};
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:           {kind: 'StructLiteralStart', text: '{'},
 // CHECK:STDOUT:           {kind: 'InvalidParse', text: 'a', has_error: yes},
 // CHECK:STDOUT:         {kind: 'StructLiteral', text: '}', has_error: yes, subtree_size: 3},
diff --git a/toolchain/parse/testdata/struct/fail_identifier_only.carbon b/toolchain/parse/testdata/struct/fail_identifier_only.carbon
index 4df4916cb70d6..1a222956f93ee 100644
--- a/toolchain/parse/testdata/struct/fail_identifier_only.carbon
+++ b/toolchain/parse/testdata/struct/fail_identifier_only.carbon
@@ -17,7 +17,7 @@ var x: {a} = {};
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:           {kind: 'StructLiteralStart', text: '{'},
 // CHECK:STDOUT:           {kind: 'InvalidParse', text: 'a', has_error: yes},
 // CHECK:STDOUT:         {kind: 'StructLiteral', text: '}', has_error: yes, subtree_size: 3},
diff --git a/toolchain/parse/testdata/struct/fail_invalid_struct_designator.carbon b/toolchain/parse/testdata/struct/fail_invalid_struct_designator.carbon
index 348afedd7f7e1..bf8e732783589 100644
--- a/toolchain/parse/testdata/struct/fail_invalid_struct_designator.carbon
+++ b/toolchain/parse/testdata/struct/fail_invalid_struct_designator.carbon
@@ -17,12 +17,12 @@ var x: i32 = {.7 = 8};
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
 // CHECK:STDOUT:         {kind: 'StructLiteralStart', text: '{'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: '7', has_error: yes},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: '7', has_error: yes},
 // CHECK:STDOUT:         {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:         {kind: 'IntLiteral', text: '8'},
 // CHECK:STDOUT:         {kind: 'InvalidParse', text: '=', has_error: yes},
diff --git a/toolchain/parse/testdata/struct/fail_missing_type.carbon b/toolchain/parse/testdata/struct/fail_missing_type.carbon
index 03fce48ab9b9d..ef0d709e7b41d 100644
--- a/toolchain/parse/testdata/struct/fail_missing_type.carbon
+++ b/toolchain/parse/testdata/struct/fail_missing_type.carbon
@@ -17,9 +17,9 @@ var x: {.a:} = {};
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:           {kind: 'StructTypeLiteralStart', text: '{'},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:           {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'InvalidParse', text: '}', has_error: yes},
 // CHECK:STDOUT:           {kind: 'InvalidParse', text: ':', has_error: yes},
diff --git a/toolchain/parse/testdata/struct/fail_missing_value.carbon b/toolchain/parse/testdata/struct/fail_missing_value.carbon
index 5c189bfc89fab..f8ce7b6153f6b 100644
--- a/toolchain/parse/testdata/struct/fail_missing_value.carbon
+++ b/toolchain/parse/testdata/struct/fail_missing_value.carbon
@@ -17,9 +17,9 @@ var x: {.a=} = {};
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:           {kind: 'StructLiteralStart', text: '{'},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:           {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'InvalidParse', text: '}', has_error: yes},
 // CHECK:STDOUT:           {kind: 'InvalidParse', text: '=', has_error: yes},
diff --git a/toolchain/parse/testdata/struct/fail_mix_type_and_value.carbon b/toolchain/parse/testdata/struct/fail_mix_type_and_value.carbon
index ce1693cf58734..065ea2143dc2d 100644
--- a/toolchain/parse/testdata/struct/fail_mix_type_and_value.carbon
+++ b/toolchain/parse/testdata/struct/fail_mix_type_and_value.carbon
@@ -17,14 +17,14 @@ var x: {.a: i32, .b = 0} = {};
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:           {kind: 'StructTypeLiteralStart', text: '{'},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:             {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'StructTypeLiteralField', text: ':', subtree_size: 4},
 // CHECK:STDOUT:           {kind: 'StructTypeLiteralComma', text: ','},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:           {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'InvalidParse', text: '.', has_error: yes},
 // CHECK:STDOUT:         {kind: 'StructTypeLiteral', text: '}', has_error: yes, subtree_size: 10},
diff --git a/toolchain/parse/testdata/struct/fail_mix_value_and_type.carbon b/toolchain/parse/testdata/struct/fail_mix_value_and_type.carbon
index 57b317dc6c7db..25bcd3792645c 100644
--- a/toolchain/parse/testdata/struct/fail_mix_value_and_type.carbon
+++ b/toolchain/parse/testdata/struct/fail_mix_value_and_type.carbon
@@ -17,9 +17,9 @@ var x: {.a = 0, b: i32} = {};
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:           {kind: 'StructLiteralStart', text: '{'},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:             {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'IntLiteral', text: '0'},
 // CHECK:STDOUT:           {kind: 'StructLiteralField', text: '=', subtree_size: 4},
diff --git a/toolchain/parse/testdata/struct/fail_mix_with_unknown.carbon b/toolchain/parse/testdata/struct/fail_mix_with_unknown.carbon
index 7ca9f0fc5ad67..7bdaced290948 100644
--- a/toolchain/parse/testdata/struct/fail_mix_with_unknown.carbon
+++ b/toolchain/parse/testdata/struct/fail_mix_with_unknown.carbon
@@ -31,41 +31,41 @@ var x: i32 = {.a: i32, .b, .c = 1};
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
 // CHECK:STDOUT:         {kind: 'StructLiteralStart', text: '{'},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:           {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'IntLiteral', text: '1'},
 // CHECK:STDOUT:         {kind: 'StructLiteralField', text: '=', subtree_size: 4},
 // CHECK:STDOUT:         {kind: 'StructLiteralComma', text: ','},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:         {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:         {kind: 'InvalidParse', text: '.', has_error: yes},
 // CHECK:STDOUT:         {kind: 'StructLiteralComma', text: ','},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'c'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'c'},
 // CHECK:STDOUT:         {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:         {kind: 'InvalidParse', text: '.', has_error: yes},
 // CHECK:STDOUT:       {kind: 'StructLiteral', text: '}', has_error: yes, subtree_size: 14},
 // CHECK:STDOUT:     {kind: 'VariableDecl', text: ';', subtree_size: 20},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
 // CHECK:STDOUT:         {kind: 'StructTypeLiteralStart', text: '{'},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:           {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'StructTypeLiteralField', text: ':', subtree_size: 4},
 // CHECK:STDOUT:         {kind: 'StructTypeLiteralComma', text: ','},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:         {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:         {kind: 'InvalidParse', text: '.', has_error: yes},
 // CHECK:STDOUT:         {kind: 'StructTypeLiteralComma', text: ','},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'c'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'c'},
 // CHECK:STDOUT:         {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:         {kind: 'InvalidParse', text: '.', has_error: yes},
 // CHECK:STDOUT:       {kind: 'StructTypeLiteral', text: '}', has_error: yes, subtree_size: 14},
diff --git a/toolchain/parse/testdata/struct/fail_no_colon_or_equals.carbon b/toolchain/parse/testdata/struct/fail_no_colon_or_equals.carbon
index dbd2dfe10a8ce..732b42731bea9 100644
--- a/toolchain/parse/testdata/struct/fail_no_colon_or_equals.carbon
+++ b/toolchain/parse/testdata/struct/fail_no_colon_or_equals.carbon
@@ -17,9 +17,9 @@ var x: {.a} = {};
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:           {kind: 'StructLiteralStart', text: '{'},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:           {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'InvalidParse', text: '.', has_error: yes},
 // CHECK:STDOUT:         {kind: 'StructLiteral', text: '}', has_error: yes, subtree_size: 5},
diff --git a/toolchain/parse/testdata/struct/fail_period_only.carbon b/toolchain/parse/testdata/struct/fail_period_only.carbon
index 34a5b15f7077d..a1e8cdcb0c0bd 100644
--- a/toolchain/parse/testdata/struct/fail_period_only.carbon
+++ b/toolchain/parse/testdata/struct/fail_period_only.carbon
@@ -17,9 +17,9 @@ var x: {.} = {};
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:           {kind: 'StructLiteralStart', text: '{'},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: '}', has_error: yes},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: '}', has_error: yes},
 // CHECK:STDOUT:           {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'InvalidParse', text: '.', has_error: yes},
 // CHECK:STDOUT:         {kind: 'StructLiteral', text: '}', has_error: yes, subtree_size: 5},
diff --git a/toolchain/parse/testdata/struct/fail_period_paren.carbon b/toolchain/parse/testdata/struct/fail_period_paren.carbon
index 7206de965caf6..7383cb210fee1 100644
--- a/toolchain/parse/testdata/struct/fail_period_paren.carbon
+++ b/toolchain/parse/testdata/struct/fail_period_paren.carbon
@@ -17,9 +17,9 @@ var x: {.(a) = 1};
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:           {kind: 'StructLiteralStart', text: '{'},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: '(', has_error: yes},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: '(', has_error: yes},
 // CHECK:STDOUT:           {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'IntLiteral', text: '1'},
 // CHECK:STDOUT:           {kind: 'InvalidParse', text: '=', has_error: yes},
diff --git a/toolchain/parse/testdata/struct/fail_period_string_colon.carbon b/toolchain/parse/testdata/struct/fail_period_string_colon.carbon
index 01dbc0b721783..b6e9ed9de7065 100644
--- a/toolchain/parse/testdata/struct/fail_period_string_colon.carbon
+++ b/toolchain/parse/testdata/struct/fail_period_string_colon.carbon
@@ -17,14 +17,14 @@ var x: {."hello": i32, .y: i32} = {};
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:           {kind: 'StructTypeLiteralStart', text: '{'},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: '"hello"', has_error: yes},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: '"hello"', has_error: yes},
 // CHECK:STDOUT:           {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'InvalidParse', text: ':', has_error: yes},
 // CHECK:STDOUT:           {kind: 'StructTypeLiteralComma', text: ','},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'y'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'y'},
 // CHECK:STDOUT:             {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'StructTypeLiteralField', text: ':', subtree_size: 4},
diff --git a/toolchain/parse/testdata/struct/fail_period_string_equals.carbon b/toolchain/parse/testdata/struct/fail_period_string_equals.carbon
index 9f8dc29de4b24..02d027ad9bc25 100644
--- a/toolchain/parse/testdata/struct/fail_period_string_equals.carbon
+++ b/toolchain/parse/testdata/struct/fail_period_string_equals.carbon
@@ -17,14 +17,14 @@ var x: {."hello" = 0, .y = 4} = {};
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:           {kind: 'StructLiteralStart', text: '{'},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: '"hello"', has_error: yes},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: '"hello"', has_error: yes},
 // CHECK:STDOUT:           {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'IntLiteral', text: '0'},
 // CHECK:STDOUT:           {kind: 'InvalidParse', text: '=', has_error: yes},
 // CHECK:STDOUT:           {kind: 'StructLiteralComma', text: ','},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'y'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'y'},
 // CHECK:STDOUT:             {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'IntLiteral', text: '4'},
 // CHECK:STDOUT:           {kind: 'StructLiteralField', text: '=', subtree_size: 4},
diff --git a/toolchain/parse/testdata/struct/fail_type_no_designator.carbon b/toolchain/parse/testdata/struct/fail_type_no_designator.carbon
index 7fd81e3974228..d2146c4501694 100644
--- a/toolchain/parse/testdata/struct/fail_type_no_designator.carbon
+++ b/toolchain/parse/testdata/struct/fail_type_no_designator.carbon
@@ -17,7 +17,7 @@ var x: {i32} = {};
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:           {kind: 'StructLiteralStart', text: '{'},
 // CHECK:STDOUT:           {kind: 'InvalidParse', text: 'i32', has_error: yes},
 // CHECK:STDOUT:         {kind: 'StructLiteral', text: '}', has_error: yes, subtree_size: 3},
diff --git a/toolchain/parse/testdata/struct/no_entries.carbon b/toolchain/parse/testdata/struct/no_entries.carbon
index 8b41c0aa1f152..d9f42ad10f0b7 100644
--- a/toolchain/parse/testdata/struct/no_entries.carbon
+++ b/toolchain/parse/testdata/struct/no_entries.carbon
@@ -14,7 +14,7 @@ var y: {} = {};
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'y'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'y'},
 // CHECK:STDOUT:           {kind: 'StructLiteralStart', text: '{'},
 // CHECK:STDOUT:         {kind: 'StructLiteral', text: '}', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 4},
diff --git a/toolchain/parse/testdata/struct/one_entry_no_comma.carbon b/toolchain/parse/testdata/struct/one_entry_no_comma.carbon
index 62c1ecc0a3e7f..528d707a1a755 100644
--- a/toolchain/parse/testdata/struct/one_entry_no_comma.carbon
+++ b/toolchain/parse/testdata/struct/one_entry_no_comma.carbon
@@ -14,9 +14,9 @@ var z: {.n: i32} = {.n = 4};
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'z'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'z'},
 // CHECK:STDOUT:           {kind: 'StructTypeLiteralStart', text: '{'},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:             {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'StructTypeLiteralField', text: ':', subtree_size: 4},
@@ -24,7 +24,7 @@ var z: {.n: i32} = {.n = 4};
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 8},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
 // CHECK:STDOUT:         {kind: 'StructLiteralStart', text: '{'},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:           {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'IntLiteral', text: '4'},
 // CHECK:STDOUT:         {kind: 'StructLiteralField', text: '=', subtree_size: 4},
diff --git a/toolchain/parse/testdata/struct/one_entry_with_comma.carbon b/toolchain/parse/testdata/struct/one_entry_with_comma.carbon
index b4f12ba42b506..994d7fefcb726 100644
--- a/toolchain/parse/testdata/struct/one_entry_with_comma.carbon
+++ b/toolchain/parse/testdata/struct/one_entry_with_comma.carbon
@@ -14,9 +14,9 @@ var z: {.n: i32,} = {.n = 4,};
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'z'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'z'},
 // CHECK:STDOUT:           {kind: 'StructTypeLiteralStart', text: '{'},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:             {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'StructTypeLiteralField', text: ':', subtree_size: 4},
@@ -25,7 +25,7 @@ var z: {.n: i32,} = {.n = 4,};
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 9},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
 // CHECK:STDOUT:         {kind: 'StructLiteralStart', text: '{'},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'n'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'n'},
 // CHECK:STDOUT:           {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'IntLiteral', text: '4'},
 // CHECK:STDOUT:         {kind: 'StructLiteralField', text: '=', subtree_size: 4},
diff --git a/toolchain/parse/testdata/struct/two_entries.carbon b/toolchain/parse/testdata/struct/two_entries.carbon
index 9176a98b99813..0d54033a2be1a 100644
--- a/toolchain/parse/testdata/struct/two_entries.carbon
+++ b/toolchain/parse/testdata/struct/two_entries.carbon
@@ -14,14 +14,14 @@ var x: {.a: i32, .b: i32} = {.a = 1, .b = 2};
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:           {kind: 'StructTypeLiteralStart', text: '{'},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:             {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'StructTypeLiteralField', text: ':', subtree_size: 4},
 // CHECK:STDOUT:           {kind: 'StructTypeLiteralComma', text: ','},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:             {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'StructTypeLiteralField', text: ':', subtree_size: 4},
@@ -29,12 +29,12 @@ var x: {.a: i32, .b: i32} = {.a = 1, .b = 2};
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 13},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
 // CHECK:STDOUT:         {kind: 'StructLiteralStart', text: '{'},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'a'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'a'},
 // CHECK:STDOUT:           {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'IntLiteral', text: '1'},
 // CHECK:STDOUT:         {kind: 'StructLiteralField', text: '=', subtree_size: 4},
 // CHECK:STDOUT:         {kind: 'StructLiteralComma', text: ','},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'b'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'b'},
 // CHECK:STDOUT:           {kind: 'StructFieldDesignator', text: '.', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'IntLiteral', text: '2'},
 // CHECK:STDOUT:         {kind: 'StructLiteralField', text: '=', subtree_size: 4},
diff --git a/toolchain/parse/testdata/tuple/access/repeated.carbon b/toolchain/parse/testdata/tuple/access/repeated.carbon
index 71a3fefecb717..b6936cf7c8204 100644
--- a/toolchain/parse/testdata/tuple/access/repeated.carbon
+++ b/toolchain/parse/testdata/tuple/access/repeated.carbon
@@ -14,7 +14,7 @@ let x: i32 = tuple.0.1.2;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'LetIntroducer', text: 'let'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'LetInitializer', text: '='},
diff --git a/toolchain/parse/testdata/tuple/access/value_access.carbon b/toolchain/parse/testdata/tuple/access/value_access.carbon
index cd9ec4488372a..75c25a697d2e0 100644
--- a/toolchain/parse/testdata/tuple/access/value_access.carbon
+++ b/toolchain/parse/testdata/tuple/access/value_access.carbon
@@ -14,7 +14,7 @@ let x: i32 = tuple.0;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'LetIntroducer', text: 'let'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'LetInitializer', text: '='},
diff --git a/toolchain/parse/testdata/tuple/nested.carbon b/toolchain/parse/testdata/tuple/nested.carbon
index 40559adb00b33..0ee0fb52d91e4 100644
--- a/toolchain/parse/testdata/tuple/nested.carbon
+++ b/toolchain/parse/testdata/tuple/nested.carbon
@@ -14,7 +14,7 @@ var y: ((), (), ());
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'y'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'y'},
 // CHECK:STDOUT:           {kind: 'TupleLiteralStart', text: '('},
 // CHECK:STDOUT:             {kind: 'TupleLiteralStart', text: '('},
 // CHECK:STDOUT:           {kind: 'TupleLiteral', text: ')', subtree_size: 2},
diff --git a/toolchain/parse/testdata/tuple/two_entries.carbon b/toolchain/parse/testdata/tuple/two_entries.carbon
index c07ea3bd6ce4b..82713df369582 100644
--- a/toolchain/parse/testdata/tuple/two_entries.carbon
+++ b/toolchain/parse/testdata/tuple/two_entries.carbon
@@ -14,7 +14,7 @@ var x: (i32, i32) = (1, 2);
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:           {kind: 'TupleLiteralStart', text: '('},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:           {kind: 'TupleLiteralComma', text: ','},
diff --git a/toolchain/parse/testdata/var/fail_bad_name.carbon b/toolchain/parse/testdata/var/fail_bad_name.carbon
index 2d4f7671bdc33..b790f624686d2 100644
--- a/toolchain/parse/testdata/var/fail_bad_name.carbon
+++ b/toolchain/parse/testdata/var/fail_bad_name.carbon
@@ -17,7 +17,7 @@ var *;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: '*', has_error: yes},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: '*', has_error: yes},
 // CHECK:STDOUT:         {kind: 'InvalidParse', text: '*', has_error: yes},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: '*', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'VariableDecl', text: ';', subtree_size: 5},
diff --git a/toolchain/parse/testdata/var/fail_empty.carbon b/toolchain/parse/testdata/var/fail_empty.carbon
index f92555b54ae47..2a72f4f727e33 100644
--- a/toolchain/parse/testdata/var/fail_empty.carbon
+++ b/toolchain/parse/testdata/var/fail_empty.carbon
@@ -17,7 +17,7 @@ var;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: ';', has_error: yes},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: ';', has_error: yes},
 // CHECK:STDOUT:         {kind: 'InvalidParse', text: ';', has_error: yes},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ';', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'VariableDecl', text: ';', subtree_size: 5},
diff --git a/toolchain/parse/testdata/var/fail_no_semi.carbon b/toolchain/parse/testdata/var/fail_no_semi.carbon
index 6b328de4ea8e0..49d09c4fc41fb 100644
--- a/toolchain/parse/testdata/var/fail_no_semi.carbon
+++ b/toolchain/parse/testdata/var/fail_no_semi.carbon
@@ -21,7 +21,7 @@ var
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: '', has_error: yes},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: '', has_error: yes},
 // CHECK:STDOUT:         {kind: 'InvalidParse', text: '', has_error: yes},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: '', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'VariableDecl', text: 'var', has_error: yes, subtree_size: 5},
diff --git a/toolchain/parse/testdata/var/var.carbon b/toolchain/parse/testdata/var/var.carbon
index c6056c9a6e584..3c78485f9fdca 100644
--- a/toolchain/parse/testdata/var/var.carbon
+++ b/toolchain/parse/testdata/var/var.carbon
@@ -18,24 +18,24 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'v'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'v'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
 // CHECK:STDOUT:       {kind: 'IntLiteral', text: '0'},
 // CHECK:STDOUT:     {kind: 'VariableDecl', text: ';', subtree_size: 7},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'w'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'w'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'VariableDecl', text: ';', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 's'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 's'},
 // CHECK:STDOUT:           {kind: 'StringTypeLiteral', text: 'String'},
 // CHECK:STDOUT:         {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/var/var_tuple.carbon b/toolchain/parse/testdata/var/var_tuple.carbon
index 4971617c3fc52..1dd569b8ce16a 100644
--- a/toolchain/parse/testdata/var/var_tuple.carbon
+++ b/toolchain/parse/testdata/var/var_tuple.carbon
@@ -16,17 +16,17 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'VariableIntroducer', text: 'var'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 's'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 's'},
 // CHECK:STDOUT:             {kind: 'StringTypeLiteral', text: 'String'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'PatternListComma', text: ','},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'i'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'i'},
 // CHECK:STDOUT:             {kind: 'IntLiteral', text: '32'},
 // CHECK:STDOUT:           {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 9},
diff --git a/toolchain/parse/testdata/where_expr/basic.carbon b/toolchain/parse/testdata/where_expr/basic.carbon
index 01a66df2126ad..777e6328ff1c7 100644
--- a/toolchain/parse/testdata/where_expr/basic.carbon
+++ b/toolchain/parse/testdata/where_expr/basic.carbon
@@ -24,9 +24,9 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'T'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'T'},
 // CHECK:STDOUT:               {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:             {kind: 'WhereOperand', text: 'where', subtree_size: 2},
 // CHECK:STDOUT:                 {kind: 'SelfTypeName', text: 'Self'},
@@ -38,13 +38,13 @@ fn F() {
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 11},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ';', subtree_size: 14},
 // CHECK:STDOUT:         {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'I'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'I'},
 // CHECK:STDOUT:       {kind: 'InterfaceDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'LetIntroducer', text: 'let'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'T'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'T'},
 // CHECK:STDOUT:               {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:             {kind: 'WhereOperand', text: 'where', subtree_size: 2},
-// CHECK:STDOUT:                 {kind: 'IdentifierName', text: 'Foo'},
+// CHECK:STDOUT:                 {kind: 'IdentifierNameNotBeforeParams', text: 'Foo'},
 // CHECK:STDOUT:               {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
 // CHECK:STDOUT:               {kind: 'IdentifierNameExpr', text: 'Bar'},
 // CHECK:STDOUT:             {kind: 'RequirementImpls', text: 'impls', subtree_size: 4},
@@ -53,29 +53,29 @@ fn F() {
 // CHECK:STDOUT:       {kind: 'LetDecl', text: ';', subtree_size: 11},
 // CHECK:STDOUT:     {kind: 'InterfaceDefinition', text: '}', subtree_size: 15},
 // CHECK:STDOUT:       {kind: 'LetIntroducer', text: 'let'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'T'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'T'},
 // CHECK:STDOUT:             {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:           {kind: 'WhereOperand', text: 'where', subtree_size: 2},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'U'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'U'},
 // CHECK:STDOUT:             {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'V'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'V'},
 // CHECK:STDOUT:             {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'RequirementEqual', text: '=', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'WhereExpr', text: 'where', subtree_size: 8},
 // CHECK:STDOUT:       {kind: 'CompileTimeBindingPattern', text: ':!', subtree_size: 10},
 // CHECK:STDOUT:     {kind: 'LetDecl', text: ';', subtree_size: 12},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'LetIntroducer', text: 'let'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'U'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'U'},
 // CHECK:STDOUT:               {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:             {kind: 'WhereOperand', text: 'where', subtree_size: 2},
-// CHECK:STDOUT:                 {kind: 'IdentifierName', text: 'W'},
+// CHECK:STDOUT:                 {kind: 'IdentifierNameNotBeforeParams', text: 'W'},
 // CHECK:STDOUT:               {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
-// CHECK:STDOUT:                 {kind: 'IdentifierName', text: 'X'},
+// CHECK:STDOUT:                 {kind: 'IdentifierNameNotBeforeParams', text: 'X'},
 // CHECK:STDOUT:               {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'RequirementEqualEqual', text: '==', subtree_size: 5},
 // CHECK:STDOUT:           {kind: 'WhereExpr', text: 'where', subtree_size: 8},
diff --git a/toolchain/parse/testdata/where_expr/designators.carbon b/toolchain/parse/testdata/where_expr/designators.carbon
index 01f3bc09244e6..7dace1a56f051 100644
--- a/toolchain/parse/testdata/where_expr/designators.carbon
+++ b/toolchain/parse/testdata/where_expr/designators.carbon
@@ -70,11 +70,11 @@ var x: i32 = .
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Success'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'Success'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:         {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'ExprStatement', text: ';', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'SelfTypeName', text: 'Self'},
@@ -87,7 +87,7 @@ var x: i32 = .
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'FailNumeric'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'FailNumeric'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
@@ -101,11 +101,11 @@ var x: i32 = .
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'FailKeyword'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'FailKeyword'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'base', has_error: yes},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'base', has_error: yes},
 // CHECK:STDOUT:         {kind: 'DesignatorExpr', text: '.', has_error: yes, subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'ExprStatement', text: ';', has_error: yes, subtree_size: 3},
 // CHECK:STDOUT:     {kind: 'FunctionDefinition', text: '}', subtree_size: 9},
@@ -115,7 +115,7 @@ var x: i32 = .
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'FailEmpty'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'FailEmpty'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
@@ -129,7 +129,7 @@ var x: i32 = .
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'FailStar'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'FailStar'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
@@ -144,7 +144,7 @@ var x: i32 = .
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'VariableIntroducer', text: 'var'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'x'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'x'},
 // CHECK:STDOUT:         {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:       {kind: 'BindingPattern', text: ':', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'VariableInitializer', text: '='},
diff --git a/toolchain/parse/testdata/where_expr/fail_rewrite.carbon b/toolchain/parse/testdata/where_expr/fail_rewrite.carbon
index ddfaf13496e7e..6966676937bb3 100644
--- a/toolchain/parse/testdata/where_expr/fail_rewrite.carbon
+++ b/toolchain/parse/testdata/where_expr/fail_rewrite.carbon
@@ -70,9 +70,9 @@ fn AfterAnd(Z:! Q where .R impls S and () = .A);
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'NotDesignator'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'NotDesignator'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'T'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'T'},
 // CHECK:STDOUT:               {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:             {kind: 'WhereOperand', text: 'where', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'IntTypeLiteral', text: 'i32'},
@@ -86,13 +86,13 @@ fn AfterAnd(Z:! Q where .R impls S and () = .A);
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'DesignatorInParens'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'DesignatorInParens'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'V'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'V'},
 // CHECK:STDOUT:               {kind: 'IdentifierNameExpr', text: 'I'},
 // CHECK:STDOUT:             {kind: 'WhereOperand', text: 'where', subtree_size: 2},
 // CHECK:STDOUT:               {kind: 'ParenExprStart', text: '('},
-// CHECK:STDOUT:                 {kind: 'IdentifierName', text: 'J'},
+// CHECK:STDOUT:                 {kind: 'IdentifierNameNotBeforeParams', text: 'J'},
 // CHECK:STDOUT:               {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'ParenExpr', text: ')', subtree_size: 4},
 // CHECK:STDOUT:           {kind: 'WhereExpr', text: 'where', has_error: yes, subtree_size: 7},
@@ -105,9 +105,9 @@ fn AfterAnd(Z:! Q where .R impls S and () = .A);
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'DotSelf'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'DotSelf'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'W'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'W'},
 // CHECK:STDOUT:               {kind: 'IdentifierNameExpr', text: 'K'},
 // CHECK:STDOUT:             {kind: 'WhereOperand', text: 'where', subtree_size: 2},
 // CHECK:STDOUT:               {kind: 'SelfTypeName', text: 'Self'},
@@ -122,12 +122,12 @@ fn AfterAnd(Z:! Q where .R impls S and () = .A);
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'DotKeyword'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'DotKeyword'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'W'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'W'},
 // CHECK:STDOUT:               {kind: 'IdentifierNameExpr', text: 'K'},
 // CHECK:STDOUT:             {kind: 'WhereOperand', text: 'where', subtree_size: 2},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'and', has_error: yes},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'and', has_error: yes},
 // CHECK:STDOUT:             {kind: 'DesignatorExpr', text: '.', has_error: yes, subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'WhereExpr', text: 'where', has_error: yes, subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'CompileTimeBindingPattern', text: ':!', has_error: yes, subtree_size: 7},
@@ -139,12 +139,12 @@ fn AfterAnd(Z:! Q where .R impls S and () = .A);
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'PostfixAfterDesignator'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'PostfixAfterDesignator'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'X'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'X'},
 // CHECK:STDOUT:               {kind: 'IdentifierNameExpr', text: 'L'},
 // CHECK:STDOUT:             {kind: 'WhereOperand', text: 'where', subtree_size: 2},
-// CHECK:STDOUT:                 {kind: 'IdentifierName', text: 'M'},
+// CHECK:STDOUT:                 {kind: 'IdentifierNameNotBeforeParams', text: 'M'},
 // CHECK:STDOUT:               {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'PostfixOperatorStar', text: '*', subtree_size: 3},
 // CHECK:STDOUT:           {kind: 'WhereExpr', text: 'where', has_error: yes, subtree_size: 6},
@@ -157,14 +157,14 @@ fn AfterAnd(Z:! Q where .R impls S and () = .A);
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'BinaryOpAfterDesignator'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'BinaryOpAfterDesignator'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'Y'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'Y'},
 // CHECK:STDOUT:               {kind: 'IdentifierNameExpr', text: 'N'},
 // CHECK:STDOUT:             {kind: 'WhereOperand', text: 'where', subtree_size: 2},
-// CHECK:STDOUT:                 {kind: 'IdentifierName', text: 'O'},
+// CHECK:STDOUT:                 {kind: 'IdentifierNameNotBeforeParams', text: 'O'},
 // CHECK:STDOUT:               {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
-// CHECK:STDOUT:                 {kind: 'IdentifierName', text: 'P'},
+// CHECK:STDOUT:                 {kind: 'IdentifierNameNotBeforeParams', text: 'P'},
 // CHECK:STDOUT:               {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'InfixOperatorPlus', text: '+', subtree_size: 5},
 // CHECK:STDOUT:           {kind: 'WhereExpr', text: 'where', has_error: yes, subtree_size: 8},
@@ -177,12 +177,12 @@ fn AfterAnd(Z:! Q where .R impls S and () = .A);
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'AfterAnd'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'AfterAnd'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'Z'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'Z'},
 // CHECK:STDOUT:               {kind: 'IdentifierNameExpr', text: 'Q'},
 // CHECK:STDOUT:             {kind: 'WhereOperand', text: 'where', subtree_size: 2},
-// CHECK:STDOUT:                 {kind: 'IdentifierName', text: 'R'},
+// CHECK:STDOUT:                 {kind: 'IdentifierNameNotBeforeParams', text: 'R'},
 // CHECK:STDOUT:               {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
 // CHECK:STDOUT:               {kind: 'IdentifierNameExpr', text: 'S'},
 // CHECK:STDOUT:             {kind: 'RequirementImpls', text: 'impls', subtree_size: 4},
diff --git a/toolchain/parse/testdata/where_expr/impl_where.carbon b/toolchain/parse/testdata/where_expr/impl_where.carbon
index bf52cc93284a7..ca0ca60a9dca2 100644
--- a/toolchain/parse/testdata/where_expr/impl_where.carbon
+++ b/toolchain/parse/testdata/where_expr/impl_where.carbon
@@ -21,10 +21,10 @@ impl bool as Interface where .T = i32;
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'InterfaceIntroducer', text: 'interface'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'Interface'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameNotBeforeParams', text: 'Interface'},
 // CHECK:STDOUT:       {kind: 'InterfaceDefinitionStart', text: '{', subtree_size: 3},
 // CHECK:STDOUT:         {kind: 'LetIntroducer', text: 'let'},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'T'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'T'},
 // CHECK:STDOUT:           {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:         {kind: 'CompileTimeBindingPattern', text: ':!', subtree_size: 3},
 // CHECK:STDOUT:       {kind: 'LetDecl', text: ';', subtree_size: 5},
@@ -34,7 +34,7 @@ impl bool as Interface where .T = i32;
 // CHECK:STDOUT:         {kind: 'TypeImplAs', text: 'as', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'IdentifierNameExpr', text: 'Interface'},
 // CHECK:STDOUT:           {kind: 'WhereOperand', text: 'where', subtree_size: 2},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'T'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'T'},
 // CHECK:STDOUT:             {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
 // CHECK:STDOUT:               {kind: 'TupleLiteralStart', text: '('},
 // CHECK:STDOUT:             {kind: 'TupleLiteral', text: ')', subtree_size: 2},
@@ -47,7 +47,7 @@ impl bool as Interface where .T = i32;
 // CHECK:STDOUT:       {kind: 'TypeImplAs', text: 'as', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'IdentifierNameExpr', text: 'Interface'},
 // CHECK:STDOUT:         {kind: 'WhereOperand', text: 'where', subtree_size: 2},
-// CHECK:STDOUT:             {kind: 'IdentifierName', text: 'T'},
+// CHECK:STDOUT:             {kind: 'IdentifierNameNotBeforeParams', text: 'T'},
 // CHECK:STDOUT:           {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:         {kind: 'RequirementEqual', text: '=', subtree_size: 4},
diff --git a/toolchain/parse/testdata/where_expr/where_and.carbon b/toolchain/parse/testdata/where_expr/where_and.carbon
index aed973dde5ebd..b85a4e35cdee9 100644
--- a/toolchain/parse/testdata/where_expr/where_and.carbon
+++ b/toolchain/parse/testdata/where_expr/where_and.carbon
@@ -41,19 +41,19 @@ fn AndEarly(Z:! L where .M and N);
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'OneAnd'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'OneAnd'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'T'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'T'},
 // CHECK:STDOUT:               {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:             {kind: 'WhereOperand', text: 'where', subtree_size: 2},
-// CHECK:STDOUT:                 {kind: 'IdentifierName', text: 'U'},
+// CHECK:STDOUT:                 {kind: 'IdentifierNameNotBeforeParams', text: 'U'},
 // CHECK:STDOUT:               {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
 // CHECK:STDOUT:               {kind: 'IntTypeLiteral', text: 'i32'},
 // CHECK:STDOUT:             {kind: 'RequirementEqual', text: '=', subtree_size: 4},
 // CHECK:STDOUT:             {kind: 'RequirementAnd', text: 'and'},
-// CHECK:STDOUT:                 {kind: 'IdentifierName', text: 'V'},
+// CHECK:STDOUT:                 {kind: 'IdentifierNameNotBeforeParams', text: 'V'},
 // CHECK:STDOUT:               {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
-// CHECK:STDOUT:                 {kind: 'IdentifierName', text: 'W'},
+// CHECK:STDOUT:                 {kind: 'IdentifierNameNotBeforeParams', text: 'W'},
 // CHECK:STDOUT:               {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'RequirementEqualEqual', text: '==', subtree_size: 5},
 // CHECK:STDOUT:           {kind: 'WhereExpr', text: 'where', subtree_size: 13},
@@ -61,23 +61,23 @@ fn AndEarly(Z:! L where .M and N);
 // CHECK:STDOUT:       {kind: 'TuplePattern', text: ')', subtree_size: 17},
 // CHECK:STDOUT:     {kind: 'FunctionDecl', text: ';', subtree_size: 20},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'TwoAnd'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'TwoAnd'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'Y'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'Y'},
 // CHECK:STDOUT:               {kind: 'IdentifierNameExpr', text: 'I'},
 // CHECK:STDOUT:             {kind: 'WhereOperand', text: 'where', subtree_size: 2},
-// CHECK:STDOUT:                 {kind: 'IdentifierName', text: 'J'},
+// CHECK:STDOUT:                 {kind: 'IdentifierNameNotBeforeParams', text: 'J'},
 // CHECK:STDOUT:               {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
 // CHECK:STDOUT:               {kind: 'IdentifierNameExpr', text: 'K'},
 // CHECK:STDOUT:             {kind: 'RequirementImpls', text: 'impls', subtree_size: 4},
 // CHECK:STDOUT:             {kind: 'RequirementAnd', text: 'and'},
-// CHECK:STDOUT:                 {kind: 'IdentifierName', text: 'L'},
+// CHECK:STDOUT:                 {kind: 'IdentifierNameNotBeforeParams', text: 'L'},
 // CHECK:STDOUT:               {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
-// CHECK:STDOUT:                 {kind: 'IdentifierName', text: 'M'},
+// CHECK:STDOUT:                 {kind: 'IdentifierNameNotBeforeParams', text: 'M'},
 // CHECK:STDOUT:               {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'RequirementEqualEqual', text: '==', subtree_size: 5},
 // CHECK:STDOUT:             {kind: 'RequirementAnd', text: 'and'},
-// CHECK:STDOUT:                 {kind: 'IdentifierName', text: 'N'},
+// CHECK:STDOUT:                 {kind: 'IdentifierNameNotBeforeParams', text: 'N'},
 // CHECK:STDOUT:               {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
 // CHECK:STDOUT:               {kind: 'BoolTypeLiteral', text: 'bool'},
 // CHECK:STDOUT:             {kind: 'RequirementEqual', text: '=', subtree_size: 4},
@@ -91,9 +91,9 @@ fn AndEarly(Z:! L where .M and N);
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'AndPrefix'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'AndPrefix'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'T'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'T'},
 // CHECK:STDOUT:               {kind: 'TypeTypeLiteral', text: 'type'},
 // CHECK:STDOUT:             {kind: 'WhereOperand', text: 'where', subtree_size: 2},
 // CHECK:STDOUT:             {kind: 'InvalidParse', text: 'and', has_error: yes},
@@ -107,12 +107,12 @@ fn AndEarly(Z:! L where .M and N);
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'AndSuffix'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'AndSuffix'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'Y'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'Y'},
 // CHECK:STDOUT:               {kind: 'IdentifierNameExpr', text: 'I'},
 // CHECK:STDOUT:             {kind: 'WhereOperand', text: 'where', subtree_size: 2},
-// CHECK:STDOUT:                 {kind: 'IdentifierName', text: 'J'},
+// CHECK:STDOUT:                 {kind: 'IdentifierNameNotBeforeParams', text: 'J'},
 // CHECK:STDOUT:               {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
 // CHECK:STDOUT:               {kind: 'IdentifierNameExpr', text: 'K'},
 // CHECK:STDOUT:             {kind: 'RequirementImpls', text: 'impls', subtree_size: 4},
@@ -128,12 +128,12 @@ fn AndEarly(Z:! L where .M and N);
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:       {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:       {kind: 'IdentifierName', text: 'AndEarly'},
+// CHECK:STDOUT:       {kind: 'IdentifierNameBeforeParams', text: 'AndEarly'},
 // CHECK:STDOUT:         {kind: 'TuplePatternStart', text: '('},
-// CHECK:STDOUT:           {kind: 'IdentifierName', text: 'Z'},
+// CHECK:STDOUT:           {kind: 'IdentifierNameNotBeforeParams', text: 'Z'},
 // CHECK:STDOUT:               {kind: 'IdentifierNameExpr', text: 'L'},
 // CHECK:STDOUT:             {kind: 'WhereOperand', text: 'where', subtree_size: 2},
-// CHECK:STDOUT:               {kind: 'IdentifierName', text: 'M'},
+// CHECK:STDOUT:               {kind: 'IdentifierNameNotBeforeParams', text: 'M'},
 // CHECK:STDOUT:             {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
 // CHECK:STDOUT:           {kind: 'WhereExpr', text: 'where', has_error: yes, subtree_size: 5},
 // CHECK:STDOUT:         {kind: 'CompileTimeBindingPattern', text: ':!', has_error: yes, subtree_size: 7},
diff --git a/toolchain/parse/testdata/while/basic.carbon b/toolchain/parse/testdata/while/basic.carbon
index 299d102d5b199..73d3d8ead90a9 100644
--- a/toolchain/parse/testdata/while/basic.carbon
+++ b/toolchain/parse/testdata/while/basic.carbon
@@ -23,7 +23,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/while/fail_missing_cond.carbon b/toolchain/parse/testdata/while/fail_missing_cond.carbon
index c5d9779a33b52..9d499564339d3 100644
--- a/toolchain/parse/testdata/while/fail_missing_cond.carbon
+++ b/toolchain/parse/testdata/while/fail_missing_cond.carbon
@@ -20,7 +20,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/while/fail_no_semi.carbon b/toolchain/parse/testdata/while/fail_no_semi.carbon
index 77d09328ac0db..59a017d7aa249 100644
--- a/toolchain/parse/testdata/while/fail_no_semi.carbon
+++ b/toolchain/parse/testdata/while/fail_no_semi.carbon
@@ -30,7 +30,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/testdata/while/fail_unbraced.carbon b/toolchain/parse/testdata/while/fail_unbraced.carbon
index 5c77acffc62ed..adc014f7f192c 100644
--- a/toolchain/parse/testdata/while/fail_unbraced.carbon
+++ b/toolchain/parse/testdata/while/fail_unbraced.carbon
@@ -21,7 +21,7 @@ fn F() {
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
 // CHECK:STDOUT:         {kind: 'FunctionIntroducer', text: 'fn'},
-// CHECK:STDOUT:         {kind: 'IdentifierName', text: 'F'},
+// CHECK:STDOUT:         {kind: 'IdentifierNameBeforeParams', text: 'F'},
 // CHECK:STDOUT:           {kind: 'TuplePatternStart', text: '('},
 // CHECK:STDOUT:         {kind: 'TuplePattern', text: ')', subtree_size: 2},
 // CHECK:STDOUT:       {kind: 'FunctionDefinitionStart', text: '{', subtree_size: 5},
diff --git a/toolchain/parse/tree_test.cpp b/toolchain/parse/tree_test.cpp
index 66bb132f09887..bacc294bebaa8 100644
--- a/toolchain/parse/tree_test.cpp
+++ b/toolchain/parse/tree_test.cpp
@@ -97,8 +97,8 @@ TEST_F(TreeTest, PrintPostorderAsYAML) {
       Yaml::Mapping(ElementsAre(Pair("kind", "FileStart"), Pair("text", ""))),
       Yaml::Mapping(
           ElementsAre(Pair("kind", "FunctionIntroducer"), Pair("text", "fn"))),
-      Yaml::Mapping(
-          ElementsAre(Pair("kind", "IdentifierName"), Pair("text", "F"))),
+      Yaml::Mapping(ElementsAre(Pair("kind", "IdentifierNameBeforeParams"),
+                                Pair("text", "F"))),
       Yaml::Mapping(
           ElementsAre(Pair("kind", "TuplePatternStart"), Pair("text", "("))),
       Yaml::Mapping(ElementsAre(Pair("kind", "TuplePattern"), Pair("text", ")"),
@@ -131,7 +131,7 @@ TEST_F(TreeTest, PrintPreorderAsYAML) {
                                 Pair("kind", "FunctionIntroducer"),
                                 Pair("text", "fn"))),
       Yaml::Mapping(ElementsAre(Pair("node_index", "2"),
-                                Pair("kind", "IdentifierName"),
+                                Pair("kind", "IdentifierNameBeforeParams"),
                                 Pair("text", "F"))),
       Yaml::Mapping(ElementsAre(Pair("node_index", "4"),
                                 Pair("kind", "TuplePattern"), Pair("text", ")"),
diff --git a/toolchain/parse/typed_nodes.h b/toolchain/parse/typed_nodes.h
index 83d9e37e8df07..1708c68170285 100644
--- a/toolchain/parse/typed_nodes.h
+++ b/toolchain/parse/typed_nodes.h
@@ -127,10 +127,17 @@ using FileEnd = LeafNode<NodeKind::FileEnd, Lex::FileEndTokenIndex>;
 using EmptyDecl =
     LeafNode<NodeKind::EmptyDecl, Lex::SemiTokenIndex, NodeCategory::Decl>;
 
-// A name in a non-expression context, such as a declaration.
-using IdentifierName =
-    LeafNode<NodeKind::IdentifierName, Lex::IdentifierTokenIndex,
-             NodeCategory::MemberName>;
+// A name in a non-expression context, such as a declaration, that is known
+// to be followed by parameters.
+using IdentifierNameBeforeParams =
+    LeafNode<NodeKind::IdentifierNameBeforeParams, Lex::IdentifierTokenIndex,
+             NodeCategory::MemberName | NodeCategory::NonExprIdentifierName>;
+
+// A name in a non-expression context, such as a declaration, that is known
+// to not be followed by parameters.
+using IdentifierNameNotBeforeParams =
+    LeafNode<NodeKind::IdentifierNameNotBeforeParams, Lex::IdentifierTokenIndex,
+             NodeCategory::MemberName | NodeCategory::NonExprIdentifierName>;
 
 // A name in an expression context.
 using IdentifierNameExpr =
@@ -154,28 +161,36 @@ using SelfTypeNameExpr =
 using BaseName =
     LeafNode<NodeKind::BaseName, Lex::BaseTokenIndex, NodeCategory::MemberName>;
 
-// An unqualified name and optionally a following sequence of parameters.
-// For example, `A`, `A(n: i32)`, or `A[T:! type](n: T)`.
-struct NameAndParams {
-  IdentifierNameId name;
+// A name qualifier with parameters, such as `A(T:! type).` or `A[T:! type](N:!
+// T).`.
+struct NameQualifierWithParams {
+  static constexpr auto Kind = NodeKind::NameQualifierWithParams.Define(
+      {.bracketed_by = IdentifierNameBeforeParams::Kind});
+
+  IdentifierNameBeforeParamsId name;
   std::optional<ImplicitParamListId> implicit_params;
   std::optional<TuplePatternId> params;
+  Lex::PeriodTokenIndex token;
 };
 
-// A name qualifier: `A.`, `A(T:! type).`, or `A[T:! type](N:! T).`.
-struct NameQualifier {
-  static constexpr auto Kind =
-      NodeKind::NameQualifier.Define({.bracketed_by = IdentifierName::Kind});
+// A name qualifier without parameters, such as `A.`.
+struct NameQualifierWithoutParams {
+  static constexpr auto Kind = NodeKind::NameQualifierWithoutParams.Define(
+      {.bracketed_by = IdentifierNameNotBeforeParams::Kind});
 
-  NameAndParams name_and_params;
+  IdentifierNameNotBeforeParamsId name;
   Lex::PeriodTokenIndex token;
 };
 
 // A complete name in a declaration: `A.C(T:! type).F(n: i32)`.
 // Note that this includes the parameters of the entity itself.
 struct DeclName {
-  llvm::SmallVector<NameQualifierId> qualifiers;
-  NameAndParams name_and_params;
+  llvm::SmallVector<
+      NodeIdOneOf<NameQualifierWithParams, NameQualifierWithoutParams>>
+      qualifiers;
+  AnyNonExprIdentifierNameId name;
+  std::optional<ImplicitParamListId> implicit_params;
+  std::optional<TuplePatternId> params;
 };
 
 // Library, package, import, export
@@ -284,7 +299,7 @@ struct BindingPattern {
   static constexpr auto Kind = NodeKind::BindingPattern.Define(
       {.category = NodeCategory::Pattern, .child_count = 2});
 
-  NodeIdOneOf<IdentifierName, SelfValueName> name;
+  NodeIdOneOf<IdentifierNameNotBeforeParams, SelfValueName> name;
   Lex::ColonTokenIndex token;
   AnyExprId type;
 };
@@ -294,7 +309,7 @@ struct CompileTimeBindingPattern {
   static constexpr auto Kind = NodeKind::CompileTimeBindingPattern.Define(
       {.category = NodeCategory::Pattern, .child_count = 2});
 
-  NodeIdOneOf<IdentifierName, SelfValueName> name;
+  NodeIdOneOf<IdentifierNameNotBeforeParams, SelfValueName> name;
   Lex::ColonExclaimTokenIndex token;
   AnyExprId type;
 };
@@ -1029,7 +1044,7 @@ struct DesignatorExpr {
       {.category = NodeCategory::Expr, .child_count = 1});
 
   Lex::PeriodTokenIndex token;
-  NodeIdOneOf<IdentifierName, SelfTypeName> name;
+  NodeIdOneOf<IdentifierNameNotBeforeParams, SelfTypeName> name;
 };
 
 struct RequirementEqual {
@@ -1104,7 +1119,7 @@ struct ChoiceDefinition {
 
   ChoiceDefinitionStartId signature;
   struct Alternative {
-    IdentifierNameId name;
+    AnyNonExprIdentifierNameId name;
     std::optional<TuplePatternId> parameters;
   };
   CommaSeparatedList<Alternative, ChoiceAlternativeListCommaId> alternatives;
@@ -1133,7 +1148,7 @@ struct StructFieldDesignator {
       NodeKind::StructFieldDesignator.Define({.child_count = 1});
 
   Lex::PeriodTokenIndex token;
-  NodeIdOneOf<IdentifierName, BaseName> name;
+  NodeIdOneOf<IdentifierNameNotBeforeParams, BaseName> name;
 };
 
 // `.a = 0`
diff --git a/toolchain/parse/typed_nodes_test.cpp b/toolchain/parse/typed_nodes_test.cpp
index 48a9d68a583f3..ce229e3179ad8 100644
--- a/toolchain/parse/typed_nodes_test.cpp
+++ b/toolchain/parse/typed_nodes_test.cpp
@@ -130,7 +130,8 @@ TEST_F(TypedNodeTest, For) {
   ASSERT_TRUE(for_var.has_value());
   auto for_var_binding = tree.ExtractAs<BindingPattern>(for_var->pattern);
   ASSERT_TRUE(for_var_binding.has_value());
-  auto for_var_name = tree.ExtractAs<IdentifierName>(for_var_binding->name);
+  auto for_var_name =
+      tree.ExtractAs<IdentifierNameNotBeforeParams>(for_var_binding->name);
   ASSERT_TRUE(for_var_name.has_value());
 }
 
@@ -230,7 +231,7 @@ Aggregate [^:]*: success
   // Use Regex matching to avoid hard-coding the result of `typeinfo(T).name()`.
   EXPECT_THAT(err2.message(), testing::MatchesRegex(
                                   R"Trace(Aggregate [^:]*: begin
-NodeIdInCategory MemberExpr\|MemberName: kind IdentifierName consumed
+NodeIdInCategory MemberExpr\|MemberName: kind IdentifierNameNotBeforeParams consumed
 NodeIdInCategory Expr: kind PointerMemberAccessExpr consumed
 Aggregate [^:]*: success
 )Trace"));
@@ -252,18 +253,16 @@ TEST_F(TypedNodeTest, VerifyExtractTraceClassDecl) {
   EXPECT_THAT(err.message(), testing::MatchesRegex(
                                  R"Trace(Aggregate [^:]*: begin
 Aggregate [^:]*: begin
-Aggregate [^:]*: begin
 Optional [^:]*: begin
 NodeIdForKind: TuplePattern consumed
 Optional [^:]*: found
 Optional [^:]*: begin
-NodeIdForKind error: wrong kind IdentifierName, expected ImplicitParamList
+NodeIdForKind error: wrong kind IdentifierNameBeforeParams, expected ImplicitParamList
 Optional [^:]*: missing
-NodeIdForKind: IdentifierName consumed
-Aggregate [^:]*: success
+NodeIdInCategory : kind IdentifierNameBeforeParams consumed
 Vector: begin
-NodeIdForKind: NameQualifier consumed
-NodeIdForKind error: wrong kind AbstractModifier, expected NameQualifier
+NodeIdOneOf NameQualifierWithParams or NameQualifierWithoutParams: NameQualifierWithoutParams consumed
+NodeIdOneOf error: wrong kind AbstractModifier, expected NameQualifierWithParams or NameQualifierWithoutParams
 Vector: end
 Aggregate [^:]*: success
 Vector: begin
@@ -352,7 +351,7 @@ TEST_F(TypedNodeTest, VerifyInvalid) {
     Error err = trace;
     EXPECT_THAT(err.message(), testing::MatchesRegex(
                                    R"Trace((?s).*
-NodeIdForKind error: wrong kind IdentifierName, expected ImplicitParamList
+NodeIdForKind error: wrong kind IdentifierNameBeforeParams, expected ImplicitParamList
 .*
 Error: ClassIntroducer node left unconsumed.)Trace"));
   }