You can lock forums to prevent users from adding new topics or posting responses to existing topics.
You must be a forum owner to lock or unlock a stand-alone forum. Administrators can lock or unlock any forum. If the forum is in a community, then community owners can also lock and unlock a forum and its topics.
Anyone who has permission to lock a forum can create topics and replies in the forum even when it is locked. Forum owners can update the forum without unlocking it. The forum and its topics remain locked for all other users.
To lock a forum, complete the following steps:
The forum is marked as locked in the user interface to advise users that they cannot contribute to the forum.