Directory bits under Unix

[fc () all net (Dr. Frederick B. Cohen)]

The situation gets far more complex in network file systems.  For
example, when a PC running PC-NFS mounts a directory on a System 5 Unix
box, things work differently than mounts on a Sun system.  In other
words, the same bits mean different things to different computers in the
same network. Want a different interpretation of protection? Go to a
different computer!

Just thought I'd add some fuel to the setgid bit fire.
FC