/proc guidelines and sysctl

I wrote an wireless ethernet driver awhile ago
(http://www.cse.ucsc.edu/~breed/airo.html) and found the /proc interface to
be an extremely useful interface to the many knobs in the card.  I am a bit
uncomfortable defining my own namespace in the /proc file system (did it
anyway:) and I've been wondering for a while if there are guidelines
somewhere on where things should go.  I would really like to tap into an
existing directory for ethX for example...

Along the same lines is there a maintainer for /proc that I could run
extension ideas by? Or should I just post to the list?

And finally, what's up with sysctl?  Are driver writers recommended to use
that over extending /proc or is it deprecated?  Again guide lines would be
nice.

/proc is a very powerful feature of Linux and has been extremely useful for
our embedded projects.  It would be nice if there were well defined
guidelines for driver developers to add to the namespace.  (If there is and
I'm just clueless, it would be nice if someone gave me a clue!)

ben