Alternative UPN suffixes
To provide additional logon security and simplify user names, you can provide alternative UPN suffixes in the Administration Web Interface. Alternative UPN suffixes allow users to authenticate with their user principal name (UPN), even if it contains an alternative domain suffix. In addition, you can provide an NT4-style domain as an alternative suffix, which is required for the name resolution of NT4-style user names with Active Directory user name resolution or simple user name resolution.
This is an alternative to Windows user name translation on Windows and is also supported on Linux.