Create skeleton

Author: BillWagner

docs/csharp/language-reference/compiler-messages/preprocessor-errors.md

@@ -0,0 +1,23 @@
+---
+title: Errors and warnings generated by the C# preprocessor
+description: Learn how to diagnose and fix errors related to preprocessor tokens how they are used in C# source files.
+f1_keywords:
+  - "CS9297"
+  - "CS9298"
+  - "CS9299"
+  - "CS9314"
+helpviewer_keywords:
+  - "CS9297"
+  - "CS9298"
+  - "CS9299"
+  - "CS9314"
+ms.date: 10/07/2025
+---
+# Preprocessor errors and warnings
+
+The compiler generates the following errors for incorrect use of preprocessor directives:
+
+- **CS9297**: *`#:` directives cannot be after first token in file*
+- **CS9298**: *`#:`directives can be only used in file-based programs (`-features:FileBasedProgram`)*
+- **CS9299**: *`#:` directives cannot be after `#if` directive*
+- **CS9314**: *`#!` directives can be only used in scripts or file-based programs*

docs/csharp/language-reference/toc.yml

@@ -460,6 +460,10 @@ items:
 - name: C# compiler messages
   href: ./compiler-messages/index.md
   items:
+  - name: Preprocessor errors
+    href: ./compiler-messages/preprocessor-errors.md
+    displayName: >
+      CS9297, CS9298, CS9299, CS9314
   - name: Feature or version missing
     href: ./compiler-messages/feature-version-errors.md
     displayName: >

docs/csharp/misc/sorry-we-don-t-have-specifics-on-this-csharp-error.md

@@ -620,10 +620,6 @@ f1_keywords:
   - "CS9235"
   - "CS9236"
 # C# 14 errors begin here
-## Shebang
-  - "CS9297"
-  - "CS9298"
-  - "CS9299"
 ## using `extension` as type name. (valid identifiers).
   - "CS9306"
 ## User defined operators
@@ -632,10 +628,22 @@ f1_keywords:
   - "CS9311"
   - "CS9312"
   - "CS9313"
-## Shebang
-  - "CS9314"
 ## Strings in the data section:
   - "CS9315"
+## More extension errors
+  - "CS9316"
+  - "CS9317"
+  - "CS9318"
+  - "CS9319"
+  - "CS9326"
+  - "CS9327"
+  - "CS9328"
+  - "CS9329"
+  - "CS9330"
+  - "CS9331"
+  - "CS9332"
+  - "CS9333"
+  - "CS9334"
 helpviewer_keywords:
   - "errors [C#], additional information"
 ---