Username is Your Site-wide Identifier, it can be used to log to SugarAsian.org.
You might apply for a Nickname, Nickname cannot be Username that log to site.
There are only two methods to log in site, by Username or Registered E-mail. How to Sign Up and Log In
Display name can be your Username and Nickname, that shows on frontend page, such as on your profile, any posts/discussions your participate, other frontend pages of site-wide.
If you don't have Nickname, your Username is your Display Name; once you have a Nickname, your Nickname will be your Display Name.
How to apply a Nickname
