Is there a way to inquire with a provider (discreetly) about what is and isn't on the menu before booking an appointment?  I tend to see independent upscale providers who are established and well-reviewed, and most of these meetings have been without surprises.  However, a couple times I have been denied services that the provider's website and reviews indicated would be available.  Nothing outlandish like BBFS, but more common stuff like LFK/DFK, DATY/FIV, BBBJ, etc.  I don't think hygiene is the issue.  I shower and brush/floss/mouthwash regularly (as well as specifically before each appointment), wash my hands and mouthwash thoroughly upon arriving, and try to stay hydrated throughout the session to avoid dry mouth and bad breath.

It literally means Your Mileage May Vary. It suggests that the reviewer got certain services but they are at the discretion of the provider. There is simply no foolproof way to get around this.  All you can do is read her web site, read her reviews and back-channel her recent reviewers.
One thing you should NOT do is ask her, because it's likely she'll cut off all communication with you.  Most girls will never discuss sex acts before the date.
Bottom line:  there is always some risk involved.  The only way to eliminate it is to stop playing this game.

then consider yourself lucky.

doing the research on the potential lady you want to visit.   If you are being disappointed by your chosen provider, it would seem to me that your research on her was somewhat weak.  I will never visit someone unless I know that she meets all my requirements for my enjoyment of her company.  As also mentioned, NEVER ask her directly is she provides a specific service.  This will only get you hung up on, or otherwise ignored by her, and possibly other providers she knows.  Jake mentioned several ways you can check out what you can expect to get in your encounter, and what you may not expect.

This suggestion must be used very carefully and only in the right situation that only you can assess.  Perhaps she has YMMV reviews, e.g., some report CIM, others no CIM; some say DFK, others no kissing; some say 2 pops, others one and done.  If you have established a decent rapport in emails, phone or text, but have not met her yet, you can sometimes refer to those reviews.  
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"Abe, Bob and Carl describe the kind of experience I hope to have with you. I think the experiences of Dan, Evan, and Frank would leave me a little disappointed."  That way, you don't have to say, "I want BBBJ-CIM." explicitly.  
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If she gets your meaning, she might reply, "Abe, Bon and Cal are three of my favorite regulars.  We always have fun together. Let's see how things go between you and me. I think you will be very happy to meet me." Or, she might say, "Sure. I'm down with that.  Some guys (Dan, Evan, Frank) just prefer a different outcome."
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You get the idea.  NOTE: Some posters do not like this suggestion. Maybe they will post their warnings, as well.

Trying to discuss services... even in a round about way... risks alienating her.  You've got to trust the reviewers & read between the lines a bit.  You'll need VIP to read the complete reviews.  There is no short cut.  Even when you are behind closed doors... only after the action has started, you can gently suggest directions you'd like to go in.  

the details in the reviews. Don't just go by the review scores. As has been said, YMMV always applies but if you read 5 reviews of provider X and all reviewers received MSOG, DFK, BBBJ, etc. then you are more likely to receive a similar experience.

Hi! As a provider I won’t see men who explicitly ask questions about the service. Every person is different and I think it depends on the mood and vibe. I always aim to give the best service (GfE) but I also see men in a higher bracket so it weeds out a lot of the guys I normally wouldn’t let do certain things.  
Hope that makes sense!

Thanks, this discussion is just what I was looking for.  In my situation, I'd like to set up a fantasy scenario to celebrate a personal milestone.  To really bring the scenario off, there are 1 or 2 things I'd like to ensure are ok.  Unfortunately, the provider that I'd like to book with has no review and is in the 2-3K range.  Normally, I'd book an initial date with her, but she's across the country so that's not really a great option.

Hello 2-3Kgirl. Thanks for checking my references and agreeing to meet with me (in a couple of weeks). I'd like to set up a fantasy scenario with you and I was wondering if you would be OK with that. I would like to be explicit in my description (Don't worry, it's not too weird. -or- I must warn you that it's kind of kinky.).  I could refer you to a story on a website, if that's OK, or I can tell you more about it directly. Is that OK with you?  If not, I will understand.

The proper advice is that he should not be seeing ANY women who have no reviews at this point, considering how badly he is doing even with girls who are reviewed, much less spending "2-3K" on a complete unknown who lives across the country. You/he are setting him up for failure.

You need as much information as possible.  More not less.  Certainly a web site, a good number of reviews.  You need what ever it takes to be able to read the complete reviews.  You might want to respectfully PM a few recent reviewers (expecting less than 100% replies).  NEVER ask anything which might compromise her security... like location details.   Limit your PM questioning to the deal breaker check boxes.