I see STT requires a back protector. Knox is recommended. My Gehricke Celtic suit from STG has CE rated back protector as part of the suit. Does STT consider this as meeting the back protector requirement? http://sportbiketrackgear2.homestead.com/gericke_celtic.html
As far as I know, it does. I've got the same suit and have been wearing it for the last 3 or 4 years. Having said that, I know that some of the Instructors have taken it out and put in a separate back protector that covers more of your lower back/tailbone area.