Duplicate questions on other SE sites?
13649
What to do with cross-site duplicates?
20138
Allow cross-posting of questions to more than one SO site
133887
Are questions closed as duplicates ever automatically deleted?
78231
Too many SE sites causes confusion
7406
When merging questions, leave the duplicate one as a placeholder
11336
How should we deal with duplicate answers?
101748
Duplicate / Similar content across many articles
107013
Can creating a duplicate site for testing and upgradation can cause duplicate content
112760
Bug when marking a question as duplicate
99359
What can be done about repetitive questions?
154354
What are efficient ways to find duplicates on trilogy sites?
38992
Is the duplicate answer flags raised for exact copies of answers of different users?
57056
Opinions on closing an older question as a duplicate of a newer question
71646
Duplicates of an outdated question
136774
Is it ok to delete question on one Stack Exchange site (for lack of response) and post it on another Stack Exchange site?
147570
Mark questions as duplicate of tag wiki
56823
Change how questions marked as duplicates by the asker are represented