diff --git a/proposals/csharp-12.0/experimental-attribute.md b/proposals/csharp-12.0/experimental-attribute.md
index a596ee17dc..06f8b436bd 100644
--- a/proposals/csharp-12.0/experimental-attribute.md
+++ b/proposals/csharp-12.0/experimental-attribute.md
@@ -29,23 +29,30 @@ namespace System.Diagnostics.CodeAnalysis
 }
 ```
 
-## Warnings
-The warning message is a specific message, where `'{0}'` is the fully-qualified type or member name.
-```
-'{0}' is for evaluation purposes only and is subject to change or removal in future updates.
-```
+## Reported diagnostic
 
-The warning is reported for any reference to a type or member that is either:
+Although the diagnostic is technically a warning (so that the compiler allows suppressing it),
+it is treated as an error for purpose of reporting. This causes the build to fail if the diagnostic
+is not suppressed.  
+
+The diagnostic is reported for any reference to a type or member that is either:
 - marked with the attribute,
 - in an assembly or module marked with the attribute,
 
 except when the reference occurs within `[Experimental]` members (automatic suppression).
 
-It is also possible to suppress the warning by usual means, such as an explicit compiler option or `#pragma`.
+It is also possible to suppress the diagnostic by usual means, such as an explicit compiler option or `#pragma`.  
+For example, if the API is marked with `[Experimental("DiagID")]` or `[Experimental("DiagID", UrlFormat = "https://example.org/{0}")]`, 
+the diagnostic can be suppressed with `#pragma warning disable DiagID`.
 
-The attribute is not inherited from base types or overridden members.
+An error is produced if the diagnostic ID given to the experimental attribute is not a [valid C# identifier](https://github.com/dotnet/csharpstandard/blob/standard-v7/standard/lexical-structure.md#643-identifiers).  
 
-The warning is promoted to an error for purpose of reporting.
+The diagnostic message is a specific message, where `'{0}'` is the fully-qualified type or member name.
+```
+'{0}' is for evaluation purposes only and is subject to change or removal in future updates.
+```
+
+The attribute is not inherited from base types or overridden members.
 
 ## ObsoleteAttribute and DeprecatedAttribute