Cross-Posting questions that are on-topic on multiple Stack Exchange sites

Question

If I have a question that is on-topic on, say, both Linux & Unix and Ask Ubuntu, may I post it on both sites? And if so, do I need to do anything special?

Answer 1

I personally don't have anything against it if it's done well but the official Stack Exchange policy on intra-StackExchange cross-posting is more clear on the topic:

Allowing cross-posting is a slippery slope.

If you might have slightly better odds of getting an answer by posting it on two sites, well, by gum, why not maximize your odds by posting it on twenty sites!

There are some questions which fall into grey areas between sites, and I think it's OK to ask and delete, then re-ask if you feel you have asked on the wrong site.

But as a general rule, do not cross-post questions, please. Pick a site and go with it.

I don't completely agree with this policy.

I don't want to confuse people too much, but the Internet is bigger than StackExchange sites and most things (be that programming or Ubuntu) have more than one support channel. I essentially don't think it would be fair for me to moderate in a way I don't behave.

A common cross-posting behaviour I engage in is asking for help with web development. I'm a StackOverflow member so [more frequently than I'd like], I'll ask a question on there and immediately ask on IRC (linking to the question on SO). I do this because this is my $DAYJOB. If I'm stuck behind some blocker, I'm losing money to it and I want help ASAP. It's completely selfish, but equally true.

With Ubuntu, I used to be a fairly active UbuntuForums poster. When I started here, I would very often post something here or there and then cross-link, or again, use IRC. I still do if it's urgent but thankfully I haven't had many super-serious issues recently.

I think I'd be a massive hypocrite if I slammed every cross-posted question as some sort of Simpsons-did-it-first-duplicate. What makes two diverse StackExchange sites more "special" than disconnected support avenues like Ask Ubuntu is to Ubuntu Forums or IRC? The same mechanics apply: you ask for help; people invest time to help you; you win.

But that doesn't mean I support all sorts of cross-posting; it's incredibly important that questions are maintained. By starting a question anywhere, you're creating a social contract: you're asking people for help and if they see an answered question, they might put [considerable] time into giving you a good answer. If you get an answer somewhere else and don't update your question here, you're wasting our users' time and I'm not okay with that.

My view on basic guidelines would be:

• Find the best location for your question.

  There are a lot of StackExchange sites, some more active than others. Remember that activity is a double-edged sword. For example, questions on the front-page of StackOverflow are on the second page within a few minutes. On a slower, site, even if there are fewer users, more people might see your question.

• If you do cross-post, cross-link them!

  Child posts should have links to the original post and if you can, try to keep the parent posts updated with a list of places you've cross-posted it to. This means that users of any site can quickly see if there have been any answers. Or post their answer on the main thread.

  If you're honest and up-front about it, we [moderators] are going to get fewer flags about it. People can track things and see if your other thread has any answers.

• Update all your threads as soon as one gets a result.

  This is probably the most important point. They you're questions so it's your responsibility to tell users on all the sites when you no longer need help. Doing this means they're not going to waste time fixing something that is already fixed.

  Do this by either answering your own question with a link to the other answer, or in the case of IRC, say what's happened, giving the user credit. Chances are you won't be able to accept your own question if you're answering it yourself, so just flag it up and we can close it for you.

  Yes, this is more work for you but that's the cost of responsible cross-posting.

This is slightly different to the path other SE sites tread. If you cross-post something on another site with a different policy, they may well outright delete your thread. That's their choice.

As a deterrent against poor cross-posting, if we notice you cross-posting without taking these steps seriously, we'll give you a warning. Twice and we'll take action to protect our users from you wasting their time.

Answer 2

The official answer to Is it possible to post questions across a couple of the sites because it's debatable which site it fits best? is:

Allowing cross-posting is a slippery slope.

If you might have slightly better odds of getting an answer by posting it on two sites, well, by gum, why not maximize your odds by posting it on twenty sites!

There are some questions which fall into grey areas between sites, and I think it's OK to ask and delete, then re-ask if you feel you have asked on the wrong site.

But as a general rule, do not cross-post questions, please. Pick a site and go with it.

If you regret your initial choice and want to change sites, I recommend flagging for migration rather than deleting and re-asking, in case someone has seen the question and is preparing an answer.

---

Unix and Linux's FAQ explicitly says not to cross-post:

Cross-posting is strongly discouraged -- if you post on one site and then change your mind it can always be migrated to another. If you're not sure if your question is on-topic, ask on meta or just give it a try and the community will decide.

So Do not post the same question on both Ask Ubuntu and Unix & Linux. When a question is cross-posted to U&L and other sites, what normally happens is that all but one instance of the question are deleted. You get a warning the first time, and doing it routinely would be considered abuse.

---

By the way, althought the term “cross-post” is often used, there is technically no cross-posting facility on Stack Exchange. A given question exists on a single site; if you post questions with identical contents, that's a multi-post.