Originally Posted by
piggi
I think the idea is that the escort calls the referee (an escort you have been with before) and gives your number to her -- a lot of girls save the 'phone numbers that punters use, rarely with a name but with a titile like "ok guy" or "nasty" or whatever. The referring escort checks the number against her phone's contact book and sees if she has seen you and if you were ok.
I agree that it is a bit over the top, and I personally have never been asked for a reference, but if I really wanted to see a particular girl I suppose I wouldn't mind.
As Patricia says, it is for each girl to choose how she operates.