Active Directory - Validate Group SamAccountName

Did a lot of digging to find the details needed so that I can write a Reg Ex to validate an AD Group SamAccountName.  Here’s what I got and I wanted to share …

(^[^. ""/\[]:|\+=;?*][^""/\[]:|\+=;?*]{1,63})(?(1)|[^.]$)

This translates to:

• Not Starting with a period (.) or a space ( ).
  • This, by design, excludes strings consisting solely of all periods (.) or spaces ( ).
• Between 1 and 64 characters (inclusive) long.
• Not including any of these characters:
  • “/[]:|<>+=;?*
• Not ending in a period (.).

If you’re like me, you want justification:

• http://support.microsoft.com/kb/938447
• http://technet.microsoft.com/library/Cc975532
• http://technet.microsoft.com/en-us/library/cc776019.aspx
• http://support.microsoft.com/kb/909264
• http://forums.techarena.in/active-directory/1011758.htm

I realize the page says 63 characters, but my testing shows 64 to be valid (Win2k8).