No. For Linux,
daemonhas swapped places -
bin used to be #1 and
daemon #2. On Minix, the #1/bin actually used to be semi-privileged by the operating system kernel (ie. a bit like #0/root). On Solaris, UID #1 is called
daemon, while GID #1 is called
others - and this is the default group for new users (with the exception of the user made during installation with the
root-"role", he belongs to the
UID #0 is of course
root... GID #0 is usually either
I think the only required user and group is #0. It's however strongly recommended to have a
daemon group too - to own //bin and //sbin. Then you often got a
systo own various system-files and directories - especially /dev (in Linux devices are now usually owned by root and lots of different groups for different groups of devices... only /dev/random, /dev/null and /dev/zero are often still got
sys as group. On other OS - like Solaris - lot of stuff is owned by
sys:sys). Often you got
adm as owner and group of various logs (originally located at /usr/adm) and sometimes run syslog. There was often a
manuser/group that owned the man-pages.
operator user and/or group was for those permitted to work at The Console - ie. the terminal connected directly to the computer in the locked computer-room. It often ran back-ups, and thus often a member of the
root-group to get access to (almost) everything.
staff is a group used for "junior-admins", perhaps allowed control over /home and add local users.
Finally we got a series of user:group pairs for various common - and to some degree - required services... some are today uncommon:
lp = printer,
news = network-news (NNTP) bulletin board,
mail = the (local) mail service,
uucp = Unix to Unix CoPy... a way to pack together stuff like mail and newsgroup-posts, and "copy" it to a remote Unix-machine. Much used when when people used mostly dial-ups.
tty = TeleTYpe... owns various terminals.
Many also had a
gamesuser. Games requiring direct access to stuff like sound-cards and video-cards, where run SetUID as this user (games)... and the
game-user was added to the groups of this hardware. This way the game got the access it needed to the hardware, without having to be run with full root-access (ie. SetUID=root). It also allowed for shared "Top Score" lists and such between all users on the system.