What consitutes a duplicate question?
13335
Someone flagged my question as already answered, but it's not
31940
Add an alert when answering a question that has at least a close vote as duplicate
3685
Confirming that my own question is a duplicate by voting to close should have immediate effect
130844
Why do positive and negative variants of the same question elicit the same answer?
116288
How can I improve questions marked as duplicate?
25926
Why can't I accept two answers for the same question?
78861
Why are there two separate boxes about duplicate questions?
10674
Avoiding asking a question that's already been asked
51087
Remove votes to close question X as a duplicate of Y if question Y is closed as a duplicate of X
105704
Question closed as duplicate with  and also shown as "Possible duplicate"
42156
What is a "merged" question?
44392
Questions closed as duplicates should include a link to the original question
48639
Why prevent duplicate questions?
111647
How to find questions closed as duplicates via the Data Explorer
117258
Is it ok to to delete and repost a duplicate question?
3426
What is a "closed" or "duplicate" question?
31470
Why was this question closed as a duplicate and not as unclear what you're asking?