One thing I've wondered... let's say Jenn starts her hybridizing program, and one of the plants she uses is an unregistered hybrid (let's call it Phal. [Tom x Sue]). The cross is successful, and the babies she blooms out are phenomenal, so of course she wishes to register the cross. However, P. Tom x Sue is still unregistered according to RHS, and she doesn't know who made the cross. Would she be allowed to register her cross as P. Bob x (Tom x Sue) or would she be forced to register the Tom x Sue first?
I know in some plants crosses from unnamed crosses- even a few generations of them- seem to be acceptable (even sometimes from unkown parentage, but not going there).
Also, I've sometimes seen selfed or sib crosses of a hybrid sold under that hybrid name- this doesn't seem quite kosher, since the genes can pair up quite different from what is typical for the hybrid. Is this legitimate naming?