[sclug] Non-human user IDs

[Will Dickson]

Can anyone either tell me about, or even better, point me at the section of 
The Fine Manual which describes, the various non-human user IDs that
are usually found on a linux box?

The two I'm most interested in are "daemon" and "nobody". Do they have
any special privileges or attributes? And is there any reason not to run a 
system service, which does not want any special privileges, as user ID 
daemon?

TIA

Will.