> 1)  Are any of the COMPAT_ options REQUIRED?  And are they recommended? 
>     One problem I have noticed is that when you remove COMPAT_43, the system 
>     doesn't let you login as ROOT!?!? 

none of the COMPAT_ options are required (at least, the last time i
checked).  COMPAT_43 is _highly_ recommended, however, because (as has
been noted elsewhere, i believe) it enables support for some 4.3BSD
ioctl()s which are still used by programs in the source tree.

> 2)  It appears that INET is required, is this true?  I really don't need 
>     any networking capability and would like to free up some more 
>     memory.  (Don't got much to begin with...B-))
> 
>     I have tried removing it (and the pdev LOOP) and received several 
>     errors.  The system still ran but SYSLOGD wouldn't run and I was 
>     receiving messages stating something about the last message being 
>     repeated NNNN times, where NNNN varied.

you pretty much need inet, even if you don't have any networking.
too many things try to set up inet sockets for it to be practically
omitted.  same with the loop (loopback network interface) pseudo-device.

> 3)  Do the "commands" need to be recompiled if the kernel changes, like 
>     removing the COMPAT_09 define?

No.  Note that if you're running 0.9 binaries, and delete the
COMPAT_09 option, they may fail to work.  (however, that's sort-of
implied by removing COMPAT_09.  8-)

> 4)  Are all of the defines documented somewhere or should I consider this 
>     a worthwhile task?

some of the defines are documented, many aren't.




chris