What should I call a highly restricted username field?

1. What is a username field?
2. What characters are not allowed in username?
3. How do I create a username?

What is a username field?

The username-field command specifies the value for the name attribute in the login form that identifies the username field. The default value of j_username follows the Java™ Platform, Enterprise Edition standard for login forms.

What characters are not allowed in username?

Usernames can contain letters (a-z), numbers (0-9), and periods (.). Usernames cannot contain an ampersand (&), equals sign (=), underscore (_), apostrophe ('), dash (-), plus sign (+), comma (,), brackets (<,>), or more than one period (.) in a row.

How do I create a username?

Your username should be simple enough to remember but hard to guess. Never use easy-to-guess numbers with your usernames (for example, address or date of birth). Don't use your Social Security number or ID number as your username. If you're struggling, try an online username generator.