Meerkats: you are right, Rebecca, the mongooses and other viverrids fit
into similar niche use situations ancestrally and therefore look similar
but they are not related any more closely than to other distant members
of Carnivora.  Otters are worlds closer, as you also thought, but not
incredibly close.
 --
 
Hybrids (actually breeding in general): Using "F" for the generation
is a common method you'll find in any reputable (and likely also some
disreputable) genetics reference.  There have been so many ferrets and
other companion animals who have been hurt (disabilities and the like)
because breeders didn't bother to learn any genetics that it is a sad
situation.  Forget looking for anything ferret-specific in terms of
books; there are none which are accurate enough to be anything except
confusing and misleading, but if breeding then do at least read some
texts on genetics by finding on websites what ones are being used for
those courses by universities.  Having such texts and actually reading
them thoroughly first still won't give a lot of needed info, but it
will show where it makes sense to use extra caution and that will help
ferrets.
 
The other sides of breeding responsibly include:
1. that buyers of ferrets have to be aware and raise the standards bar
by asking breeders for health and longevity records of their lines to
study beforehand, not just statements, but actual records of what medical
problems were present and at what ages, what deformities in the lines,
what handicaps in the line, and at what ages they passed away.
2. people who acquire ferrets from breeders need to pass this info back
to the breeder to keep the records most accurate
 
Done right, the ferrets from small breeders can be healthier than the
typical ferret; done wrong they can be a lot less healthy than the
typical.  It should be no surprise that the healthiest and the least
healthy lines tend to be from small locations.
[Posted in FML issue 4083]