Username not accepted for signup

If you see an error message saying your username is in use or contains unacceptable characters:

• Please note that usernames can only contain letters and numbers, with no spaces in between.
• There is a bit of a glitch in the signup form where the system doesn't re-check the new information you entered into the username field until you click into another field. Please try again, and if the first username you put into the username field is already in use, type another username and then tap or click into any other field on the form. That should reset the checking mechanism and allow your unique username to be accepted.