Table:Automatic banning of users based on format

Discussion
I have noticed that fake user accounts seems to be spewing up, that all match two different formats: ^[a-z0-9]{9}$ or ^[a-z]+[0-9]{4}$. Which is to say that either is it a nickname of seven random alphanumeric characters or a random set of letters followed by four random numbers. Just check the user creation log.

As such, I have banned these two names. Although, this effectively means I have banned usernames of 9 characters in length, as I cannot figure out a regex that insures that both letters and numbers appear in the name. --Sviptalk 11:20, 5 July 2012 (CEST)