Password entry

[Perry Hutchison]

In article <10975 at boulder.Colorado.EDU> bobk at fred.colorado.edu (Bob Kinne)
writes:

>What is the purpose of the following /etc/passwd entry?
>
>::0:0:::	(null login, password, and shell)

On SunOS, an entry just like this except for a leading + means that login
should consult the YP (formerly "yellow pages", name changed due to
trademark issues) for additional valid logins.  This mechanism allows a
local Sun network to maintain one net-wide password file instead of having
to try to keep N separate files (one per system) up to date.

I suspect that the cited entry serves a similar purpose on your variety
of UN*X.