Historical locks are sometimes applied to questions.

  • What is a historical lock?
  • What is the purpose of a historical lock?
  • How are questions affected by historical locking?
  • When is it appropriate to lock a question for historical reasons? When is it not appropriate?
  • How do I request a historical lock for a question?
  • What should I do if I notice a serious problem with a historically-locked question or one of its answers?

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1 Answer 1


What is a historical lock?

A historical lock is a mechanism by which moderators can mark posts as historical artifacts. Questions which are historically locked feature the following post notice:

Locked. This question and its answers are locked because the question is off-topic but has historical significance. It is not currently accepting new answers or interactions.

This is an example of a question with a historical lock: Changes to syntax highlighting

What is the purpose of a historical lock?

A historical lock preserves content that was very popular when it was originally posted, but is now off-topic or otherwise out of scope for the site it is posted on. Historically locking a post ends the debate over whether a question should be kept on the site or deleted, and is often the final state of a question that has been deleted and undeleted more than once, or subject to a close or delete war.

How are questions affected by historical locking?

In addition to the post notice being prominently displayed, posts which are historically locked are "frozen in time": they cannot be voted on, flagged, answered, edited, bountied, or commented on (though they can be bookmarked, and ♦ moderators can edit and comment; moderator edits to historically locked posts do not bump the posts). The visual appearance of the entire post is altered by removing the voting arrows from the question and all answers.

Additionally, on main (non-meta) sites, historically locked questions are omitted from normal question lists (those on the home page, /questions, and the various per-tag lists), but can still be found by searching for words in the post or title (via either site-search or Google, etc.) or by using the search operator locked:1.

When is it appropriate to lock a question for historical reasons?

Questions can be historically locked when:

  1. The post does not meet the current guidelines for a good, on-topic question, and
  2. The post is stellar, in spite of its off-topic nature, and
  3. There are a large number of views, upvotes and inbound links on the post, and
  4. The post is contentious; e.g., it has been closed and reopened at least once, or deleted and undeleted at least once.

When is it not appropriate to historically lock a question?

Questions should not be historically locked if they are being actively maintained or have little or no redeeming value.

A good rule of thumb: If the question does not minimally meet site co-founder Jeff Atwood's third rule in the "We Hate Fun Here" blog post, it's probably not a good candidate for historical locking. The third rule is:

Does this question teach me anything that could make me better at my job? Can I learn something from it?

How do I request a historical lock on a question?

Flag the question for moderator attention and explain why you think the post should be historically locked. A moderator will evaluate the question using the criteria outlined above and will either lock the question or decline your flag with an explanation.

Alternatively, if you want to try and gain more community support for the question, or contest the moderator decision, you can post a question on the per-site meta.

What should I do if I notice a serious problem with a historically-locked question or one of its answers?

The system prevents you from being able to flag historically-locked posts; this is because these posts have tended to get lots of frivolous flags in the past. Therefore, if you notice a serious problem with a historically-locked post (e.g., a broken link that has since started serving spam or malware, content that is blatantly offensive, or substantiated requests to have a historical lock removed), post a question on the per-site meta explaining the exact problem. (If the locked question is here on Meta Stack Exchange itself, post your request here on this site with the tag .)

You should reserve this for serious issues like the ones above, rather than minor issues like grammar fixes or things that go against the rationale for historical locks.

If the issue is non-controversial, easily explained, and easily rectified (e.g. the broken link or blatantly offensive content mentioned above), you can alternatively raise an "in need of moderator intervention" flag on another post (usually one of your own posts). In your flag, be sure to link to the post you're actually flagging about and explain both the issue and how you feel it should be corrected.

Anything else I should know about historical locks?

  • If there was already a bounty on a question before it got historically locked, it will not be cancelled, but the bounty owner cannot award the bounty to anyone. It can still be automatically awarded, though. If there are no answers eligible for automatic awarding, consider letting a moderator know to clear the bounty to remove the question from the list of bountied questions.

  • While no new votes can be cast and users cannot retract their past votes, scores on historically-locked posts can still change as a result of vote invalidations, such as the serial vote detection script reversing votes, manual voting invalidations by staff, or a user who voted on the post being removed (and their votes weren't preserved).

  • 6
    "The post is contentious; i.e. it has been closed and reopened at least once." People frequently want questions to be historically locked without thinking they deserved to be reopened. I'll occasionally vote to reopen defensively, but that's not typical behaviour (yet).
    – Jeremy
    Commented Mar 23, 2012 at 6:24
  • Thanks, that does help. There are plenty of questions that have lots of votes and views that someone might call "useful", but no one would describe as "stellar", such as the one I mentioned in my post.
    – agf
    Commented Apr 14, 2012 at 22:44
  • 4
    why was the boat programming question deleted instead of historically locked?
    – Ephraim
    Commented May 7, 2012 at 22:04
  • 3
    @Ephraim: See here: blog.stackoverflow.com/2009/04/joke-questions-please-refrain
    – user102937
    Commented May 7, 2012 at 22:20
  • 1
    @RobertHarvey, I don't know how to search for historically locked questions; I'm assuming there's some sort of syntax to do that, but I'm not familiar with it. So I'm not actually sure how to find one to check.
    – vpn
    Commented Aug 16, 2017 at 0:27
  • 2
    @vpn meta.stackoverflow.com/questions/311535/…
    – user102937
    Commented Aug 16, 2017 at 0:29
  • @RobertHarvey, can I search for historical locks only, not for any locks? Commented Oct 7, 2017 at 23:08
  • stackoverflow.com/search?q=locked%3A1+historical+significance Returns only 2 results. Is it true? Commented Oct 7, 2017 at 23:25
  • Close/reopen votes are also not possible on a historically locked question, right?
    – Luuklag
    Commented Nov 4, 2019 at 16:09
  • Are there instances of historically locked questions that are then later deleted? Say, if the same question is instead asked on an appropriate SE site.
    – pkamb
    Commented Jun 14, 2020 at 7:47
  • @pkamb "What's your favorite math joke" was deleted on MathOverflow after having been in a historically-locked state for years, as many of the jokes were deemed to not conform to the Code of Conduct (some were blatant violations of it). Commented Sep 20, 2020 at 21:08
  • @Luuklag As the answer says, they can't be voted on; this includes both up/down votes and close/delete votes. Commented Sep 20, 2020 at 21:09
  • @Shog9 Regarding your May 2012 edit (revision 6): that seems to have been broken since January 2016. As far as you're aware, why are historically-locked questions on meta sites hidden now as on main sites? Was there some feature change later made, or was it always buggy? Commented Sep 20, 2020 at 21:11
  • A lot of related logic was rewritten over about a 2 year period there. Couldn't pinpoint which change broke it, but I'd guess the logic just didn't get ported to a replacement system. @sonic
    – Shog9
    Commented Sep 20, 2020 at 21:17
  • Can the phrase "Historical significance" be added to this answer and the question so that it shows up when that phase is googled...? I couldn't find this post when I needed it because of this... Commented Oct 8, 2020 at 4:45

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