Thus spake Luke Mewburn ("LM> ") sometime Today...

LM> Our "defacto" mechanism is that variables are tested against "no",
LM> even "yes/no" variables, because there's no simple way to enforce
LM> that such variables may only contain those two values, and it's easier
LM> to have a single consistent check (== "no", or != "no") than cater for
LM> all the various alternatives.

Minor observation:

MOST variables are thus tested, except for the few which are tested
against (re_type) .if[n]*def, something which has caused me great
consternation and confusion on occasion ("Hey, I just defined this
to be 'no', why's it still defining/including this stuff?").

Perhaps it would be better to have one file in /usr/share/mk
(bsd.defaults.mk? bsd.init.mk?) which sets up all the default values
before /etc/mk.conf gets included, with no conditional checking (leave
that to the "real" .mk files to fix up)?  Just a thought...

				--*greywolf;
--
NetBSD: the free unix for the rest of us.