What is a "locked" post?

Note: There are three types of locks in the system that work differently from most locks: the "historical significance" lock, the "comments only" lock, and the "policy" lock. Such types of locks are not covered here, but you can find information about them in the following posts:

• What is a historical lock, and what is it used for?
• How do comments work? (section "Why can't I comment on specific posts even if I have enough reputation to comment?")
• New post lock available on meta sites: Policy Lock

What does it mean to lock a post?

On locked posts, the following actions cannot be performed by non-moderators:

• Editing
• Voting
• Commenting or upvoting existing comments
• Voting to delete or undelete the post

For locked questions, the following actions also cannot be performed:

• Posting new answers
• Voting to close or reopen the question
• Offering bounties
• Protecting or unprotecting the question

Locking the question does not by itself lock any of the existing answers, so those actions can still be performed to answers (unless they are themselves locked).

Locked posts can later be unlocked by diamond moderators at any time. Optionally, they can be configured to be automatically unlocked after a certain period of time. Common temporary locking periods are 1 hour, 24 hours, or 1 week.

Who can lock a post?

Only diamond moderators can manually lock or unlock posts. If you believe that a post should be locked, flag it for moderator attention and explain why.

Additionally, the Community user locks and unlocks posts in specific circumstances (see When does the Community user lock and unlock posts below).

When should a post be locked?

Posts should generally only be manually locked in cases where something seriously bad is happening. In particular, where the ongoing updates and edits are actively detrimental to the system.

Some examples of when a post might be manually locked include:

• A post where repeated voting or editing is happening in a way which attempts to game, hack, or otherwise abuse the system.
• A post that multiple users are edit-warring or rollback-warring over and can't decide which revision to keep.
• A question that gets opened and closed repeatedly many times without achieving community consensus on whether it should stay open or closed.
• A question that, for whatever reason, continues to attract flame posts, spam, or other inappropriate answers.
• A question that is repeatedly vandalized by its asker; for example, to drastically alter the meaning of the question that invalidates existing answers, or to obliterate/obscure the question.
• A question that attracts many answers that are really the same thing over and over again.

Another type of manually locked post is a merged question. When a moderator merges two questions that are exact duplicates, all the answers are moved to one question and the other question is left as a "stub," with no answers. The stub question is locked.

A full list of reasons moderators can apply when locking a post can be found at https://meta.stackexchange.com/a/172592 (scroll down to "locked").

What if I disagree with the lock applied to a post?

If you have a justifiable reason that a post should be unlocked, you should flag it for moderator attention using the "flag" link underneath the post. Select the "other" flag reason, and provide a detailed explanation of your rationale in the textbox provided.

A moderator will review your flag, and if they agree with your arguments, unlock the post.

When does the Community user lock and unlock posts?

The Community user will lock posts under the following circumstances:

• The post receives 6 spam or "rude or abusive" flags, or a single flag from a diamond moderator (it will also be deleted by Community).
• The question is migrated to a different site (Community will lock the migration stub)
• The question was migrated from a different site, then rejected (if the destination question gets deleted, or closed for any reason other than as a duplicate, while the migration stub question still exists on the origin site, Community will lock it)*

You may sometimes see a lock from the Community user with no corresponding migration or deletion event: in that case, it was a migration, but a moderator later cleared the question's migration history.

The Community user will unlock posts under the following circumstances:

• If a post has been configured by moderators to unlock after a certain period of time, Community will unlock it once that time lapses.
• If a question that was migrated gets rejected by the destination site, Community will unlock the original (former migration stub) question.
• If a question is migrated to another site, and the migration is blocked, Community will unlock it immediately after locking it. (Note that the lock and unlock will appear reversed in the post's history; this is a known bug.)

Anything else I should know about locking?

• Locking a post will prevent it from being automatically deleted by the Community user as part of the Roomba scripts, unless it is locked as a migration stub or a rejected migration.

• While bounties cannot be started on locked questions, if the question gets locked while there is already an existing bounty, the bounty starter can still award the bounty.

• Users cannot award bounties to locked answers. However, locked answers are still eligible to be automatically awarded bounties.

• While votes cannot be cast or retracted once a post is locked, scores on locked posts can still change due to vote invalidations, such as automated serial voting reversals, if a user who voted on the post deletes their profile and their votes aren't preserved, and manual vote invalidations by staff.

* Occasionally, the migration events may not appear in the post's history, if a moderator has cleared the question's migration history. However, if the question was locked at the same time as getting closed as "Not suitable for this site", this was probably the cause.