That's when using "Human Grade" in a pet food title or definition. That's the same for everything. "Holistic" and "Natural" have no regulations, either. "Organic" is the only title slightly monitored, but it doesn't mean every ingredient has to BE organic, it just has to include a couple organic ingredients.
But food for human consumption isn't looked over so passively. Just think, if they let a label like that fly so loosely, what else will the FDA Center for Veterinary Medicine let slide? FDACVM is a lot more lax in their regulations, hence the reason pet foods always end up with recalls. I wouldn't be surprised if that division sits around and plays xbox snacking on ho-hos and twinkies until someone calls to complain about a sickness due to a certain pet food hehe