Another story, from many years ago: I once sat at a table with some rowdy semi-drunk people in a café that had live musicians. The music, if I remember correctly, was lively Scandinavian accordion music (This is Minnesota, after all.)—polskas, hambos, etc.—and some people at my table got the idea they wanted to dance. There was no dance floor as such, so they got up and danced in the space between the tables.

The manager came over and politely told them they had to stop because, he said, "we don't have a dancing license."

There was some consternation at our table because no one had ever heard of a "dancing license" and we thought maybe the manager was pulling our leg or just being a jerk.

Looking back, I now infer that the PROs have different levels of licenses, and they charge more for venues that allow customers to dance.

I suppose there is no limit on the kinds of licenses they theoretically might sell, and the kinds of restrictions they might put on each kind. It's all just a matter of what marketing strategy they want to pursue.