There are several deluded bitches with pages and pages of rules and regulations in order to book them.
I saw one who required a coffee meet or dinner or somesuch - charged at her hundreds per hour rate - Then she "decides" if she is happy to allow you to book her for more...... I do wonder how many mugs have spent a few hundred quid just to get the chance to spend another couple of hundred quid to book her for a s**g...