[atsaloli]

You can have multiple user accounts with UID 0. They will all be priveleged superusers.

Back in umpteen-umpty-umph, we used to have multiple accounts like that for different departments each with their own password. So you could track use of superuser accounts by department for some degree of accountability.

This was on Solaris 2.something but I don't see why it wouldn't work like that on other UNIX systems. It's the UID of 0 that makes an account a superuser, not the username.