Merge 7b5935e5cb into 7bc016bda6

changelogs/client_server/newsfragments/2210.removal

@@ -1 +0,0 @@
-Remove unintentional intentional mentions in replies as per [MSC4142](https://github.com/matrix-org/matrix-spec-proposals/pull/4142).

content/client-server-api/modules/rich_replies.md

@@ -64,16 +64,11 @@ as if it were to be under `m.relates_to` directly instead.
 
 #### Mentioning the replied to user
 
-{{% boxes/note %}}
-{{% changed-in v="1.16" %}}
-Clients SHOULD no longer propagate mentioned users in the replied to event.
-{{% /boxes/note %}}
+In order to notify users of the reply, it may be desirable to include the `sender`
+of the replied to event and any users mentioned in that event. See
+[user and room mentions](#user-and-room-mentions) for additional information.
 
-In order to notify users of the reply, it MAY be desirable to include the `sender`
-of the replied to event. See [user and room mentions](#user-and-room-mentions) for
-additional information.
-
-An example including mentioning the original sender:
+An example including mentioning the original sender and other users:
 
 ```json
 {
@@ -88,6 +83,8 @@ An example including mentioning the original sender:
       "user_ids": [
         // The sender of $another_event.
         "@alice:example.org",
+        // Another Matrix ID copied from the m.mentions property of $another_event.
+        "@bob:example.org"
       ]
     }
   },