Answered and closed by the same user
31654
Closing Etiquette: Why Do Some Answer *and* Close?
41718
As a new user without much rep, what should I do if someone else has already asked a question I have, but it has no answers?
42404
When answering, could we be informed that "the following people are already answering this question"?
11336
How should we deal with duplicate answers?
105704
Question closed as duplicate with  and also shown as "Possible duplicate"
4056
Can we clarify to the OP that their question is not yet closed and the duplicates are only suggestions?
52067
Etiquette for suggesting a user accept a different answer?
57718
Answers to a deleted question not deleted?
16806
Accept Multiple Answers or Split Bounty among Several Users
148502
Two accepted answers
134595
Posted questions after last seen
127414
How was this new user able to post two questions less than 40 minutes apart?
93630
"Answerer" and "asker"
133926
What if 2 answers are essentially the same?
16630
Allow users to mark "accepted" answer on someone else's question?
81081
Can a single user post two answers for one question?
158101
User deleting code after question has been answered