Adding usernames that begin w/ a number

[Chance D Ellis <ellis@xxxxxxxxxxxxxxxxxx>]

Hi again,

I am running Slackware Linux 2.0.30. I have a naming system for accounts
that I really can't change. 

all accounts on the box begin with 4 numbers and end in 4 letters. When
running 1.2.13 I had no problem adding new users with this convention.
But now, it tells me that they are invalid user names.

Is there some sort of a file that I need to setup my account
preferences?

Any help is much appreciated!!

TIA

Chance Ellis
WSCC IS Admin