My sense is that it's not the use of a specific term (with the exception of the obvious). It's the implication of "quid pro quo" that attaches to a term. Most laws on the books define prostitution as an offer of, or request for, sex in return for something of value - a quid pro quo - or "this for that." Offering to pay per meet in conjunction with an expectation (or at least the implication of) sex meets the definition - or I surmise that is SA's legal teams' stated opinion, and therefore SA's policy.
It seems that POT SB's get a lot more latitude on this than POT SD's do. You can guess why as well as, or better, than I can. But I think that SD's are much less likely to report a POT SB for using per meet language, so that may contribute.
So the TOS does not need to include a lengthy list of banned terms. In fact, they probably deliberately avoid that in case some new term arises out of nowhere that might equate to PPM. An example: In the last few years, the term "shawty" has arisen as a reference to a woman. In my decades of life, we had many other slang terms for a woman like "chick," "seat cover," "dame," "babe," "hottie," etc. But no "shawtys," thank you.
So terms are much less important than context. Sadly I have yet to see a SD who was banned for something other than quid pro quo language.
As I've said before, the closest I ever get to this, if pressed by a POT before she's willing to move to text is to mention a long list of non-sex date-like activities (dinner, a movie, shopping, drive up the coast, etc.) and then tell her I'd be happy to help her cover some bills once in a while.
Life is good
The Cat