Question posted twice despite following the question posting process only once
72826
New question asking form sometimes leads to accidental double posts of questions
112256
Should I still post an answer if I see several answers have already been posted while writing an answer or making a fiddle?
24179
Comment posting issue
127896
When to ask multiple questions in a single post ? (Revisited)
69602
Why does Super User site appear twice in vote-to-close dialog?
150227
Multiple posts with one loop iteration
95882
Typo in First Posts queue
104491
Single question thread with multiple questions, some duplicates
116288
How can I improve questions marked as duplicate?
56823
Change how questions marked as duplicates by the asker are represented
10293
How should duplicate questions be handled?
82853
Can Community ♦ raise a duplicate content flag when an answer is deleted and re-posted as a new answer?
8310
'Possible duplicate' comment not appearing for questions with deleted comments containing the link
28716
Is it OK to ask a duplicate question on purpose?
136112
comments are being saved twice on a file when i refresh the webpage
33805
Migrated question's answers can be upvoted twice by the same user
134595
Posted questions after last seen