Should there be a way to close a question as a duplicate of a question from another site?
13649
What to do with cross-site duplicates?
94974
Asking similar questions - process?
126766
Move questions between Stack Exchange sites
143078
Is there a way to migrate a question to a SE site not on the "belongs on" list?
47803
Answering the same question across the site
131299
Changes to "close as duplicate"
146225
Duplicate questions on other SE sites?
111780
How should we deal with questions that fit on more than one Stack Exchange site?
71646
Duplicates of an outdated question
105704
Question closed as duplicate with  and also shown as "Possible duplicate"
55508
Should I copy my answer to a duplicate question to the original question?
32895
How can I avoid asking duplicate questions?
154856
Wording of "possible/exact duplicates" when closing the question
126330
Wrong wording of close message when question is closed as duplicate of more than one
100366
What is best way to find duplicate questions?
3385
Automatically redirect anonymous user from unanswered duplicate question to corresponding answered version
18509
Does the new guidance on duplicate questions suggest closing a question as duplicate, if the original answers the OP's question?