It is and there are official classifications for that. Ibérico is about the race, pata negra (black paw) being a best subclass name that expanded to anything first class. If a Spaniard says you are pata negra, it's actually good, not an indictment on your feet higiene :)

Bellota (acorn) the diet. You can find intermediate categories like "50% raza ibérica" or "recebo" for both.