Perhaps the way to go is by starting with you own level of tolerance or comfort because, as you said, it is your business and, more importantly, it is your body. To me, all services that might be provided are YMMV. Why? If the customer presents himself/herself as clean and hygienic, and is respectful in his/her manner, then the escort may usually be prepared to provide services, and maybe even those not advertised. So, the YMMV caveat really should not be something for you, as the provider, or the customer to over-think. That is, YMMV is (or should be) understood as a direct reference to your level of tolerance/comfort. But if you feel it's important to spell it out, then no harm in doing so. And as for the restricted list, simple: put down on it things you absolutely will not do and is not open to negotiation, period. By spelling things out, and being specific about services on your restricted list, you are being clear, which customers that come to you, and even those who won't, will understand and can respect.