Determine a format for usernames

[MarkOates]

I'm considering removing spaces from usernames. I have always liked how allegro.cc allows a login to include spaces and have always wanted to allow spaces in usernames on my apps, but it's not conventional. I'm now leaning toward not permitting them.

Here are a few questions I'm pondering regarding usernames:

• Contain spaces?
• Allow mixed case?
• Be different from the login (in login/password)?

[MarkOates]

Plan to go with username conventions that are the same as allegro.cc

• mixed cases alphanumeric characters
• numbers
• spaces within characters
• dashes - within characters
• trimmed (no leading or trailing whitespace)
• unique (obviously)
• generates a unique handle (may not be dependent on unique name)