Index: docs/shaer-c2s-api.md
===================================================================
--- docs/shaer-c2s-api.md	(revision 5143ccf71a67b09507bf3dc89dc40fb1c5fb90cc)
+++ docs/shaer-c2s-api.md	(revision 30871c19bf329fcc6ba2eb4c80c4450c11a044e8)
@@ -84,6 +84,9 @@
 
 **Followers and following** are count-only for the public (privacy). With the
-owner's bearer they return the real entries as AS2 actor references with display,
-so a client shows names and avatars instead of bare ids:
+owner's bearer they return the real entries. By default these are bare id
+strings; send `Prefer: return=representation` (FEP-9876) to get them enriched as
+AS2 actor references with display, so a client shows names and avatars instead of
+bare ids. The server echoes `Preference-Applied: return=representation` and sets
+`Vary: Prefer`:
 
 ```json