Are users allowed to chose their names with no restriction?
30033
What are the rules governing display names and avatars?
86451
Are usernames required to be unique?
128678
Is it possible to get the User Id without the authorization?
6391
Reserved words as names or identifiers
115429
How can I make a fake name when I use command blocks?
8138
What is the intended purpose of having a "Real Name" field in user profiles?
79178
Allowing users to edit only their page and nobody else's
76268
Legality of using names in a game?
20342
Checking the way to stop duplicate names - validation rules or triggers
111904
What should be maximum and minimum length of persons User Name & Password?
49447
How do I remove my name from a post, in accordance with CC BY-SA?
107850
Can I restrict a user to use special programs?
9508
How to reply to one user among two having same names?
12907
What characters are allowed for the display name?
32498
Should a suspended account be able to mark a question as a favourite?
59116
Are there rules for forming adjectives from names?
46311
Expand the username auto-completion to everyone who can be notified