I'm not talking about the art, but the venue. For example, if a college wants to offer a martial arts class. The college has nothing to do with your art, but are giving you a space and a salary in order for you to teach the art. Or if you want to teach classes at the Y.
If I were to go to one of these places and they asked for my credentials, I could show them my 3rd Dan certificate from Kukkiwon. They wouldn't necessarily know what it is, but I would be certified and that would be enough for their credentials check.
But if I were to go in and do a boxing class, how do I verify to them that I know enough to teach boxing?
If the college is hiring a physics professor, the dean might not be a physicist. So they look at the credentials of the applicant. If they have a degree in Physics, they are trusting the college that gave them the degree that they are a legit physicist.