where num is a decimal integer, name and leader are printable strings excluding the characters .LR ? , .LR = , .LR + , .LR - , .LR / , and .LR : , and members is a comma-separated list of such strings. Such a line defines a user and a group with the given name ; the group has a group leader given by leader and group members given by the user names in members . The leader field may be empty, in which case any group member is a group leader. The members field may be empty.
Lines beginning with .L # are ignored.
The num in a line is a number used internally by a file server; there should be no duplicate num s in the file. A negative num is special: a user with a negative num cannot attach to the file server. The file /adm/users itself is owned by user adm , having a negative num , and write protected to others, so it can only be changed via console commands.