A file that provides a little exciting surprise for the subject. They are taken deep into trance and then given a fun post hypnotic suggestion. For example...at a ceratin time they become gently aroused. The subject would then be made to forget that this has been implanted and will therefore get a pleasant surprise as soon as it happens. It would only be a safe bit of harmless fun and the effect therefore needs to be not overly drastic and not permanent. There is plenty of scope to a file like this I think!