What Characters to allow for Usernames?
51375
Why would one limit username format?
115301
Can I Prevent Enumeration of Usernames?
47603
Usernames as Advertising or Spam?
136275
Validating user's UTF-8 name in Javascript
12805
Validate a username and password against Active Directory?
16686
How to \input{} files with Unicode names?
144666
Getting basic-auth username in php
144982
Certain usernames not displaying at all
4511
What characters are allowed in the HTML Name attribute inside input tag?
105633
What characters are valid for JavaScript variable names?
30033
What are the rules governing display names and avatars?
62904
Create users dynamic names and assgin roles
72668
Dealing with "difficult" usernames in targeted comments
23683
Flagging mechanism for offensive usernames
122215
regex for Twitter username
28256
What is the best email username to use for a myname.com domain?
120391
What are the security risks of allowing all characters in the website URL?