Cross-site duplicates
13649
What to do with cross-site duplicates?
107358
Duplicated content - how to tell Google I am original author
32251
Search for "similar questions" across multiple sites?
45300
How to prevent duplicate usernames when people register?
148444
Same content over multiple sites
47826
Duplicating Environments
3757
Why are there separate copies of the Terms of Service per site, if the link in each site just goes to Stack Overflow's version?
70074
How to handle a deliberate duplicate question
149615
Webmaster Tools, www and no-www, duplicate content and subdomains
94049
Does www and non-www suffer duplicate content penalty?
12835
How to efficiently find positions of duplicates?
154354
What are efficient ways to find duplicates on trilogy sites?
53245
Can I declare a duplicate page via javascript for google?
137083
Is it OK to copy parts of an answer from one SE site to an answer on another SE site?
101748
Duplicate / Similar content across many articles
33449
Why does Stack Overflow allow duplicate display names?
131801
How do I merge changes from a development copy of the site to the live site without losing new content?