Badges? We don't need no stinking badges!

I was in Houston recently, and it was only my second visit to the city. During a trip to St. James in 2016 and to Houston Dolls last weekend I noticed something that I have never seen in any other strip club – the girls are required to wear their entertainer's license (or whatever it's called) so that it is clearly visible while they work. Of the seven Houston clubs I've visited, only these two places required this. FWIW, these clubs are half a mile from one another north of downtown near the airport, but at two other somewhat nearby clubs, this was not the case.

I talked to a waitress at Houston Dolls who said she was also required to buy a $300 license and display it even though she was (more or less) fully clothed and does not dance. Not entirely unexpectedly, the licenses display the girls' real names.

I understand that many states and municipalities require strippers to purchase an entertainer's license. What I'm wondering is why are girls at these clubs required to display them – and why not at other clubs?