JSI Tip 3191. What is the maximum number of user accounts in a single Windows 2000 domain?

In tip 1023, I described the Windows NT 4.0 limits.

The design limit for the number of user accounts in a Windows 2000 forest is 2**32, ~ 4 billion accounts.

Windows 2000 Active Directory has been tested with over 30 million user accounts in a single domain.