Peter Seebach asks:
> Is there a documented procedure for installing updates of /etc?  I haven't
> installed most of /etc since pre-1.0 days, but I'm not sure what's safe
> and what isn't.  Is there a good strategy here?

I generally just diff -c the new version against what I have installed, and
figure out which differences I like.  This is mostly because the current
scheme of simply overwriting what's installed isn't safe in the presence of
local customization, rather than being a result of my watching out for gotchas
like erasing /scratch (or /stuff ;-).

A nicer /etc installation procedure might do something like saving the
officially installed version in /etc/etc.base, diffing the current version
in /etc against the base version, then patching the new official copy 
appropriately.  Unfortunately, patch isn't omniscient, and the kinds of
changes one makes to (say) /etc/rc are the kinds of changes patch would
have the most trouble sorting out, but at least the process of discovering
which files need more careful attention can be automated easily.

(It has occured to me that a major flaw in my argument about the historic
meaning of "scratch" as applied to /scratch is that traditionaly, operating
systems did not enforce rigid time limits on scratch tapes; instead, this
duty was left to other users and bored operators to enforce in a capricious
and ill-defined manner... ;-)