Lets say I'm trying to set up an appointment with a provider I've never seen before and I want to know if they are okay with Greek and dato how would I go about asking them? Up until now I usually wait until I've seen them before, but sometimes there are things I want to know if they are okay with before I even see them.

Your best bet is to check reviews and see ladies who have a rep for being anal queens. Often, their ads will specifically reference "Greek visits," and you can bet that it'll be available unless she's having a bad day. You could also try posting an ISO on your regional board.  

If you are p411 verified that's the only place I know where you can visibly 'see' what a lady offers if not reading it in her reviews if she honors them. Just don't ask. It's classless IMO. There are things you 'do' and things you simply 'don't' in this world. And asking is just not one of them. But I will say, as like anything here, there's always an exception to the rule with some here. Always. So in that essence, you may get away with it without a hitch.  

Most menu information can be found in her reviews and profile or on her website. If the do your research you shouldn't have to ask. While some may be fine with the question, asking about specific sex acts before you have met is a good way to never meet her.

That was pretty much what I figured. I'll just stick to what I've been doing and just waiting until after I've seen them once and then ask about anything I don't see in their reviews

You have to read reviews, which means you need VIP membership here to get the whole story on her.

In compliance with new Canadian law.

If she does Greek in her reviews, does not automatically mean she will with you. She might need to see how large your dick is and how you are in general with her. So I would suggest keep on doing what you are doing and always choose ladies who have Greek in their reviews. No point trying to push a hooker to do something she does not do.

You have now reached the point where TER VIP is now a reasonable investment.  You could then search on anal and anything else you like... - read the reviews and see who floats your boat.  After verification - this should be pretty easy to work out.

The act of "asking" is a crime. As mentioned, review details are your best indicator of activities they enjoy.