Disk quotas and the like: is there a standard?

The one thing that UNIX (at least the UNIX's that I've worked with) doesn't
seem to deal with is disk quotas.  One of the things that I liked about
VMS was the ability to set quotas, set a sort of "grace" quota above that,
and be able to give a user the privilege to exceed disk quotas.

Something comparable under UNIX would be useful, and no doubt there are
quite a few flavors that do use quotas ... the question being, are
disk quotas part of the POSIX standard?  What flavors of UNIX out there
do have a quota scheme?

Inquiring minds want to know ...
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Michael Stefanik, Systems Engineer (JOAT), Briareus Corporation
UUCP: ...!uunet!bria!mike
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technoignorami (tek'no-ig'no-ram`i) a group of individuals that are constantly
found to be saying things like "Well, it works on my DOS machine ..."