Well, I had my first experience in a long, long time in DC and it was very good.  Do I give the provider my username or is there an id number to give them and then ask them to write a review for me?  Thanks!

Providers don't write reviews, customers do.

ask her to whitelist you when her legs stop shaking.

I understand that I give her a review.  I just thought there is somewhere they can write about us so when providers look at our history they can see we were a good client, and are trustworthy.

No, there is no where for a provider to write a glowing review about your session. The best you can hope for is that they white list you (which is a providers way of verifying your credibility as a client).

Or, as an alternative, you can always ask them to provide you with a reference when you wish to see another lady.

We can't give guys reviews but you can use her for a reference if you see another provider. It would be a good idea to send her an email first and ask if it is ok to use her for a reference. I don't mind doing this for my clients, most of them travel a lot and want to see someone in other cities. As long as they are safe and respectful I will give them a good reference.

She can white list you.  That is not however a written review but a simple acknowledgment that she saw you and you where OK.

Be aware however that most providers want actual current references from other providers for verification.