User names and passwords must follow these guidelines:
A user name cannot contain an asterisk (*), comma (,), colon (:), or a new-line or carriage-return character.
A user name or password must be at least one character long.
If a user name or password contains a space, the entire name or password must be enclosed in quotation marks.
There is no limit on the length of passwords or user names, except for command shell restrictions on the maximum number of characters that can be entered on a command line.