Clem Cole <clemc@ccc.com> wrote:

> I'm sure it was used in many other ways, but that was certainly one scheme
> we used at UCB when wnj added them.  Again check the 4.2 docs, where the
> BSD group scheme is explained.   This did seem useful and System V picked
> it up also fairly soon after BSD released it to the world, and fortunately
> did not change the BSD semantics.

Not so soon, really. The new group scheme was widely released with
4.2 BSD (~ 1983). System V didn't pick up multiple groups until
System V Release 4, circa 1989.

Arnold