We use the following Regular Expressions for Login Name And Password on all system users. Seems to be working quite well and forces our clients to implement some proper password security:
Login Name : /^[A-Za-z0-9_@.]{8,80}$/
THIS SPECIFIES: 8 - 80 Charachters (Alpha Numeric and Special Characters _ . @) - To allow email addresses as login names as well.
Password : /?=.*[a-z](?=.[A-Z])(?=.\d)[A-Za-z\d!@#$%^&()-]{8,}/
THIS SPECIFIES: 1 Upper 1 Lower 1 Number (Longer than 8-), Special Charachters !@#$%^&()- are also allowed
Hope this helped. Feel free to use it!
Kind Regards
Hein