diff --git a/schemas/common-schema.json b/schemas/common-schema.json
index c1e0500..e955107 100644
--- a/schemas/common-schema.json
+++ b/schemas/common-schema.json
@@ -52,7 +52,7 @@
   },
   "bases": {
     "type": "string",
-    "enum": ["RV32I", "RV32E", "RV64I", "RV64E"]
+    "enum": ["Any", "RV32I", "RV32E", "RV64I", "RV64E"]
   },
   "implDefBehavior": {
     "type": "boolean"
diff --git a/tests/norm-rule/expected/test-norm-rules.html b/tests/norm-rule/expected/test-norm-rules.html
index 77daace..e948e90 100644
--- a/tests/norm-rule/expected/test-norm-rules.html
+++ b/tests/norm-rule/expected/test-norm-rules.html
@@ -228,8 +228,8 @@ <h1 class="grand-total-heading">82 Normative Rules: Includes 19 Implementation-D
               <td>Rule's "kind" property</td>
             </tr>
             <tr>
-              <td>[RV32I, RV32E, RV64I, RV64E]</td>
-              <td>Rule's "instances" property</td>
+              <td>Any</td>
+              <td>Rule's "instance" property</td>
             </tr>
             <tr>
               <td rowspan=2 id="clarification-without-text">clarification-without-text</td>
diff --git a/tests/norm-rule/expected/test-norm-rules.json b/tests/norm-rule/expected/test-norm-rules.json
index 878ddad..447cf39 100644
--- a/tests/norm-rule/expected/test-norm-rules.json
+++ b/tests/norm-rule/expected/test-norm-rules.json
@@ -80,10 +80,7 @@
       "kind": "base",
       "impl-def-behavior": false,
       "instances": [
-        "RV32I",
-        "RV32E",
-        "RV64I",
-        "RV64E"
+        "Any"
       ],
       "tags": []
     },
diff --git a/tests/norm-rule/test-ch1.yaml b/tests/norm-rule/test-ch1.yaml
index 74ce217..2a035b9 100644
--- a/tests/norm-rule/test-ch1.yaml
+++ b/tests/norm-rule/test-ch1.yaml
@@ -31,7 +31,7 @@ normative_rule_definitions:
     instance: RV32I
   - name: all_bases
     kind: base
-    instances: [RV32I, RV32E, RV64I, RV64E]
+    instance: Any
   - name: clarification-without-text
     tag: "norm:clarification-without-text"
     clarification-link: https://www.github.com/riscv/jfkd/issues/67