Here's our Windows NT Tip for.. June 15, 1999
Click Here to see a complete list of all of our previously released Tips!
Valid User Names
Each user in a domain or computer must have a unique user name. A user name can include up to 20 characters, including upper- and lowercase letters, numbers, and punctuation. The following characters cannot appear in a user name:

= + [ ] / \ < > ; : ' " * ?

You should establish a network policy for user names. Consistent naming conventions make it easier to remember user names and to find them in lists.

If your network includes users of DOS and Windows 3.1, it makes some sense to restrict user names to eight characters. Then, user names also can be used as the names of users' home directories.