> "man usermod" makes no mention of "usermod -a" on my system (Sarge). -a > is simply not listed as one of the options
You need a better distribution, then :-)
>From the WBEL4 man page :-
"If the user is currently a member of a group which is not listed, the
user will be removed from the group. This behaviour can be changed via -a
option, which appends user to the current supplementary group list."
(The "-a" is underlined, but I can't do that in email)
