This subject seems to be causing a stir with a few. I really don't know what the big deal is. Some guys need to remember that these ladies and not just the ones that ask for a reference / referral work under their own rules, not how a client perceives how they should work for him.
If the lady feels she would like extra security in the knowledge that the person ringing them is a genuine client and has seen other ladies then so be it. Isn't it a sign that she has the lights switched on and doesn't want to get caught out by a timewaster / reporter / idiot. It's not going to be fool proof but at least it's better than not asking and taking a chance of a no show.
Maybe she doesn't want to see guys that has never been with an escort before and if he gives a name then at least she knows he has (I say that loosely), that's HER decision.
Will it work every time, probably not, will it cut down on the assholes, probably will, same goes for will it alienate the odd genuine client, maybe it will but lads, you need to remember, this is all her decision and I'm sure she has weighed the pros and cons herself.
I've seen a mention of the reference system on the boards, this has nothing to do with that. It's a more personal spot check.
Before all these agencies came along this was a far more practiced system. Alas maybe guys have got so use to calling agency girls that don't really have a choice on who they see and as clients know no better.
I for one would be more than happy to give a lady that sort of information, at least then I as a client have a good sense of what type of lady I am going to see and it more than reassures me of her authenticity.