What does "usg" stand for?

[Doug Gwyn <gwyn>]

> System V is currently in the hands of AT&T Information Systems, in a group
> which, I think, used to be the UNIX System Development Laboratory in Bell
> Labs, which may have been called the UNIX Support Group before that (the
> UNIX/TS people).  That group is in Summit, NJ; I think the group in IL is
> reponsible for getting that to work on machines other than the 3B2, which is
> now the official "porting base" of UNIX.

Last time I looked at UNIX on a 3B2, several files in /usr/include/sys
had definitions for 3B2 machine-specific stuff such as memory management
unit register bit fields.  Some "porting base".