docs: update SelectiveGapicGeneration usage doc

Google APIs · copybara-github · commit 06a20b286850 · 2026-03-31T18:42:49.000-07:00
PiperOrigin-RevId: 892649773
diff --git a/google/api/client.proto b/google/api/client.proto
@@ -126,6 +126,8 @@ message CommonLanguageSettings {
   repeated ClientLibraryDestination destinations = 2;
 
   // Configuration for which RPCs should be generated in the GAPIC client.
+  //
+  // Note: This field should not be used in most cases.
   SelectiveGapicGeneration selective_gapic_generation = 3;
 }
 
@@ -501,6 +503,8 @@ enum ClientLibraryDestination {
 
 // This message is used to configure the generation of a subset of the RPCs in
 // a service for client libraries.
+//
+// Note: This feature should not be used in most cases.
 message SelectiveGapicGeneration {
   // An allowlist of the fully qualified names of RPCs that should be included
   // on public client surfaces.
