A post can be locked.
- What does it mean to lock a post?
- Who can lock a post?
- When should a post be locked?
Note: The below answer only applies to posts locked for reasons other than "historical significance" or "comments only". These types of locks work differently, and more info can be found here:
- What is a historical lock, and what is it used for?
- How do comments work? (section "Why can't I comment on a specific post?")
On locked posts, the following actions cannot be performed by non-moderators:
For locked questions, the following actions also cannot be performed:
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.
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).
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:
Another type of 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").
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.
The Community user will lock posts under the following circumstances:
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 that was migrated from another site is later locked for any reason, any lock reason notice applied will not be shown, and instead the "migration rejected" notice will be shown, even if it's not actually a rejected migration. This is a rare edge case that the team has decided they won't fix.
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.
* 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 off-topic, this was probably the cause.