Retire SER001: vector sets are not experimental any more

Directory.Build.props

@@ -10,9 +10,9 @@
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <CodeAnalysisRuleset>$(MSBuildThisFileDirectory)Shared.ruleset</CodeAnalysisRuleset>
     <MSBuildWarningsAsMessages>NETSDK1069</MSBuildWarningsAsMessages>
-    <!-- SER002/SER003/SER006/SER007/SER008 retired (Redis 8.4/8.6/8.8/8.10 features, and geo-redundant
-         failover, no longer experimental); IDs reserved, see Experiments.cs -->
-    <NoWarn>$(NoWarn);NU5105;NU1507;SER001;SER004;SER005;SER009</NoWarn>
+    <!-- SER001/SER002/SER003/SER006/SER007/SER008 retired (vector sets, Redis 8.4/8.6/8.8/8.10 features,
+         and geo-redundant failover, no longer experimental); IDs reserved, see Experiments.cs -->
+    <NoWarn>$(NoWarn);NU5105;NU1507;SER004;SER005;SER009</NoWarn>
     <PackageReleaseNotes>https://github.com/StackExchange/StackExchange.Redis/releases</PackageReleaseNotes>
     <PackageProjectUrl>https://seredis.dev/</PackageProjectUrl>
     <PackageLicenseExpression>MIT</PackageLicenseExpression>

docs/exp/SER001.md

@@ -1,15 +1,25 @@
-At the current time, [Redis documents that](https://redis.io/docs/latest/commands/vadd/):
+# SER001 — retired
+
+**This diagnostic is no longer produced.** Vector set support in current library versions is not marked
+experimental, so nothing emits `SER001` and no suppression is needed. The page is kept because the
+diagnostic's help link pointed here, and older builds still carry it.
+
+If you have a suppression for `SER001` — in a `csproj`, a `.editorconfig`, or a `#pragma` — it is now
+inert, and can be removed whenever it suits you.
+
+## What it used to mean
+
+At the time, [Redis documented that](https://redis.io/docs/latest/commands/vadd/):
 
 > Vector set is a new data type that is currently in preview and may be subject to change.
 
-As such, the corresponding library feature must also be considered subject to change:
+The corresponding library feature therefore had to be considered subject to change too:
 
-1. Existing bindings may cease working correctly if the underlying server API changes.
-2. Changes to the server API may require changes to the library API, manifesting in either/both of build-time
-   or run-time breaks. 
+1. Existing bindings might cease working correctly if the underlying server API changed.
+2. Changes to the server API might require changes to the library API, manifesting in either/both of
+   build-time or run-time breaks.
 
-While this seems *unlikely*, it must be considered a possibility. If you acknowledge this, you can suppress
-this warning by adding the following to your `csproj` file:
+Acknowledging that was what the suppression meant:
 
 ```xml
 <NoWarn>$(NoWarn);SER001</NoWarn>
@@ -19,4 +29,9 @@ or more granularly / locally in C#:
 
 ``` c#
 #pragma warning disable SER001
-```
+```
+
+## Reserved, not recycled
+
+`SER001` is not reused for anything else, so an old suppression cannot silently hide an unrelated
+warning. The same applies to the other retired identifiers — see `Experiments.cs`.

src/RESPite/Shared/Experiments.cs

@@ -8,9 +8,10 @@ internal static class Experiments
         // note: {0} is substituted with the DiagnosticId by the analyzer, e.g. .../exp/SER002
         public const string UrlFormat = "https://seredis.dev/exp/{0}";
 
-        // Retired experiments: these server features are now stable and no longer gated.
+        // Retired experiments: these features are now stable and no longer gated.
         // The DiagnosticIds remain reserved (do NOT reuse them) so old callers' suppressions
         // and the /docs/exp pages stay meaningful:
+        //   SER001 = vector sets
         //   SER002 = Server_8_4  (Redis 8.4 features)
         //   SER003 = Server_8_6  (Redis 8.6 features)
         //   SER006 = Server_8_8  (Redis 8.8 features)