[AccessD] Let's discuss lookup tables a bit more

After our discussion on normalization I've simplified the table structure
in the animal tracking database quite a bit. I especially appreciated the
idea that all animals have birth parents -- they just won't always be
known. I've expanded that to cover institutions too -- all animals come
from an institution, just sometimes, it's our own (ie, they're born here).

But that brings me to an interesting possibility regarding the institution
table. There won't be very many because we work with just a few in our
region. I'm leaning toward thinking of the institution table as a lookup
table. At least, I can use it that way, even if, traditionally, it wouldn't
be. However, they'll need the ability to add institutions on the fly, but
that's no big deal.

Any warnings?

Thanks!
Susan H.