Add Edit Attachments permission documentation

source/administration-guide/onboard/advanced-permissions.rst

@@ -203,6 +203,26 @@ Example: As the default for the entire system, only allow users to edit their ow
 3. In the **All Members**, **Channel Administrators**, and **Team Administrators** panels, in the **Manage Posts** section, check the box for **Edit Posts**.
 4. From any panel, select the gear button to set the global time limit to ``300`` seconds.
 
+Restrict who can edit post attachments
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+From Mattermost v11.8, system admins can use the **Edit Attachments** permission to control whether users can add or remove file attachments when editing posts.
+
+The **Edit Attachments** permission is separate from **Edit Own Posts**. Users with permission to edit a post can still update the post text, but they can't add or remove file attachments unless **Edit Attachments** is also enabled.
+
+By default, **Edit Attachments** is granted to users who have permission to edit posts.
+
+To allow users to edit post text without changing attachments:
+
+1. Go to **System Console > User Management > Permissions**.
+2. Select **Edit Scheme**.
+3. In the applicable role panel, go to **Manage Posts**.
+4. Enable **Edit Own Posts**.
+5. Disable **Edit Attachments**.
+6. Select **Save**.
+
+If a user sees **Post attachments cannot be edited** when editing a post, they don't have permission to add or remove attachments for that post.
+
 Integration management
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