Originally posted by Akhran
In fact for most of the entries in /etc/group, there is no entry for members of the group (i.e. no entries after the last colon).
Only members whose PRIMARY group-membership isn't
set in /etc/paswd need to be listed in /etc/group. That is,
if nobody was member of a group nobody (with that being
defined as his default group in passwd) and you also wanted
him to be member of nogroup you'd need to make him a
member of that in /etc/group