tldr: If a question turns out to be an unintentional duplicate of another site's question (and OP does not oppose due to intended different audience) allow cross-site dupe closing.

I asked this question on unix.SE, which turns out to be basically a duplicate of this SU question. Both sites are considered equally valid (although I'd rather see these questions on unix than on SU) for the question, but were both questions on the same site mine would most likely be closed as a duplicate. Migrating either question is against common sense since neither is off-topic, but that is currently the only way to close as duplicates. I therefore request:

Allow to close questions that are on-topic on multiple site to be duplicate-closed without requiring senseless migration

Examples (please expand if you have some):

Side-note: I consider this quite different from the Close as cross-post request (closed as duplicate of the link to cross-posts request for some reason), since a cross-post is the same question asked on multiple site on purpose to get potentially different answers. This request is however about being able to close a question as an accidental duplicate to another question that may actually already have "the" answer.

  • 2
    Whoah, quick downvotes :-/ Any reason other than the "Different communities may yield different answers" one? If the author of the question in question themselves realizes the question doesn't need another answer, why should it remain open instead of encouraging a redirected user from the one community to add their valuable information to the other community's question? Oct 17, 2012 at 18:47
  • It's too extreme of an edge case to worry about.
    – user102937
    Oct 17, 2012 at 19:02
  • 1
    @RobertHarvey Because I only named the one example I experienced myself? I'm sure there are more, although I admit they (should) only pose a small percentage. I mean I wouldn't call it critical, but it is a broken window nonetheless. Oct 17, 2012 at 19:04
  • 4
    I don't think cross-site duplicates is a valid concept. I've seen people claim that a question should be closed because it has already been answered somewhere else on the SE network, but it's really a baseless claim; questions are only duplicates if they are duplicates on the site in which they were asked.
    – user102937
    Oct 17, 2012 at 19:15
  • 1
    If you find a situation like that, inform the OP. At best they could add a link into their post for others to see. And if they were to implement such a dupe closure, it should not affect any possible post-ban. After all, we can't expect the OP to do a cross-site search for dupes.
    – Bart
    Oct 17, 2012 at 19:16
  • Nor should we expect a casual observer to search the entire network for an answer to their question, if it clearly belongs on one particular SE site.
    – user102937
    Oct 17, 2012 at 19:21
  • 3
    @Robert I'm not sure I follow your argument. If I ask a Wordpress question on Stack Overflow that has a good dupe on Wordpress.SE, why should it be answered anew on SO instead of dupe-closed? That stuff happens all the time and the only solution currently is to flag the dupe for migration to WP.SE. Wouldn't it be better for the question to stick around on the original site for the next asker to find?
    – Pekka
    Oct 18, 2012 at 8:26
  • 1
    No one should be expected to actively look through all sister sites that might contain dupes. But if an answered dupe happens to be found, and the questions do obviously not "clearly [belong] on one particular SE site", to quote @RobertHarvey, then the current system - either leaving both open, or migrating despite on-topicness just to dupe-close (although the automatic redirection fortunately skips this) - is flawed Oct 18, 2012 at 8:32
  • @Bart I agree you cannot ask anyone searching for cross-dupes, but what do you mean by post-ban? Oct 18, 2012 at 8:32
  • @tobias Users who ask particularly bad questions can be automatically banned from asking further questions. We don't know exactly what the algorithm is, but having your questions closed does seem to count against you. Having this all affected by a question of yours being closed for a dupe on another site seems unfair.
    – Bart
    Oct 18, 2012 at 8:47
  • @Bart Ah yes, that should of course not be held against one, agreed Oct 18, 2012 at 8:56
  • @Pekka Thanks for the agreement. Please feel free to add some examples if you happen to stumble upon some, that would probably strenghen our position Oct 18, 2012 at 9:22

3 Answers 3


What I feel I see on Drupal Answers pretty regularly:

  • Question gets closed as off-topic, with comment pointing on Stack Overflow or Server Fault question about the same thing.
  • After some time this closed question gets deleted.
  • Next person asks the very same question, as he wasn't able to find it.

Closing as duplicate instead of off-topic would serve the same purpose duplicates are not auto-deleted: it would give users entry points, provide search results, thus preventing unneeded, pointless posts. I don't mind automatic -1 for being off-topic on cross-network duplicates for being off-topic as well. The main text should still say "off-topic".

.htaccess, css, HTML and few more topics on DA suffer from lack of this feature - or maybe that's only how I feel, I'm under 10k so I can't really go and see.

  • Posted as separate request
    – Mołot
    Sep 27, 2013 at 9:37
  • +1 - A new request might be worth a shot, your request is more about leaving migrated questions in place so the search will show new users that they're on the wrong site while my (suboptimal) one is about duplicate closing of posts that are on-topic on both sites Sep 27, 2013 at 9:37

Different Q&A sites are different. A question can be on-topic on multiple sites at the same time. There wouldn't be different Stack Exchange sites if they were meant to be one single forum.

Hence, it is not a duplicate post if it is on-topic on, say, SuperUser and a similar question already exists on ServerFault. They are different sites.

  • 3
    Well, that's exactly why the OP is suggesting this feature, isn't it?
    – Pekka
    Oct 18, 2012 at 8:24
  • @Pekka: Maybe he means they're just not to be closed if they're on-topic. Nov 9, 2012 at 0:39

We just had a post on mathematics.se that was an exact duplicate of one on puzzling.se. The one on puzzling had some good answers. I posted a comment with the link, but it seems that we should be able to close the math one. I don't know how. As I was looking for links I found a duplicate on math as well, here and can't find the recent one I am talking about. Here is one post from puzzling, but I don't think it is the one I was thinking about so they have dupes as well. I think this is a strong case for closing any question as a dupe to another site (if we can find it).

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .