Do you find that "At Discretion" as in "DFK at discretion", "OWO at discretion" and "Anal at discretion" is simply prossie speak for:
"I put this up as a marketing ploy to attract punters but didn't actually, really mean to do it"
and as for "Anal at discretion", do you find that you are nearly, always told "you're too big"?
I believe it's largely for marketing purposes, but it's not the only reason. I saw a regular girl recently, who lists oral without at discretion only, rather than just oral without. She does exactly the same for French kissing, CIM and swallow. All at discretion only. Now the first time I saw her, I asked her if all were on offer and she said yes, according to hygiene. I also get the feelling that some girls will pick and choose who to perform those services for too, based on other factors.
Of course, as I suggested to her. The simple answer would be to just list all of the services without mentioning discretion and put a caveat in her profile stating that all of them depended on hygiene. Like I said, however, I'm sure that with some, other factors come into play.