dream.tent, if you have attended any private session trackdays (like RCA trackdays) with the use of sepang transponders, the printout will have 4 sectors. So i know what silvias13 is asking about but unfortunately i do not have the answer.
Please refer to the photo.. it has S1, S2, S3 and S4.
http://a2.sphotos.ak.fbcdn.net/hphotos-ak-ash2/37490_432352841848_743126848_4851168_3658084_n.jpg