<p>We can close questions as duplicate and refer to an existing question on stats.stackexchange, we should be able to do the same when there is a similar (cross-posted or not) question already existing on another stackexchange website (currently it is only possible to deal with this in the comments and you see this for instance a lot between math-overflow and math.stackexchange).</p>

<p>The current way how the question has been closed is confusing. I would say that it is not off-topic, but the off-topic category has just been (ab)used in order to close it.</p>

<p>Sure, the way that it is handled is ok, and the clarification in the comments explains sufficiently why it has been closed. Also Gung explains well how this category can be used more ambiguously. </p>

<p>But for an average user that encounters this situation again and wonders how to deal with closing a cross-posted question, it will be unlikely that he/she is aware of this meta-question or is gonna find it quickly. </p>

<p>If cross-posting is a good reason to close a question then this solution should be more clearly available in the options to close a question (instead of currently being ambiguously contained in the off-topic section, while not strictly being off-topic).</p>
