Update content/client-server-api/modules/recent_emoji.md

Co-authored-by: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>

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

@@ -3,9 +3,9 @@
 {{% added-in v="1.18" %}}
 
 This module enables clients to track a user's cumulated emoji usage across different
-devices. The data is stored in the [`m.recent_emoji`](/client-server-api/#mrecent_emoji)
-global account data event and can, among others, be used to generate recommendations
-in emoji pickers.
+devices. The data is stored in the [`m.recent_emoji`](#mrecent_emoji)
+global [account data](#client-config) and can, among other things, be used to
+generate recommendations in emoji pickers.
 
 #### Events
 
@@ -28,9 +28,13 @@ SHOULD limit the length of the `recent_emoji` array by dropping elements from
 its end. A RECOMMENDED maximum length is 100 emoji.
 
 To enable future extension, clients MUST tolerate and preserve array elements
-within `recent_emoji` that they don't understand or support. This means ignoring
-the entries when deciding what to display to the user while retaining them when
+within `recent_emoji` regardless of whether they understand or support the
+contained `emoji` value. This means ignoring entries with unrecognised values
+of `emoji` when deciding what to display to the user while retaining them when
 modifying the array (unless the modification is for truncation).
 
+To prevent undefined behavior, clients SHOULD remove array elements that
+don't conform to the event schema such as elements with negative counters.
+