A locked topic is a topic which is no longer open for replies or modifications to its posts.

Commonly, locking topics is done as an act of moderation, because the members posting in the topic have gotten out of hand, or because the topic was posted in error. Sometimes, topics are also locked when the subject they were about is no longer prevalent, but this is less common.

If a moderator locks a topic, the topic starter cannot unlock it.

There is no limit to the number of topics which may be locked, although it is uncommon to lock most topics (as this will stifle conversation.)