correct (PAM) syntax for per-user "no limit" on a resource

[Jim Breton <jamesb-debian@alongtheway.com>]

What is the correct way to give unlimited usage of a particular resource
for a specific user?

I want my own account to have a couple of exemptions from the default
resource limits, and one of them should be unlimited CPU time.

How should I do this?  I have tried:

jimb          -       cpu             unlimited

and

jimb          -       cpu             0


The "unlimited" attempt gives me an error in syslog:

Apr 10 15:41:02 tarkin pam_limits[10646]: wrong limit value 'unlimited'

and ends up giving me the default limit.

Otoh, using "0" sets my cpu time limit to literally 0, but I'm not
confident that this is a "good thing."  Is 0 understood to be no limit,
or to be literal 0 which will cause something to break at some point?

Thanks.