Organic disulphides (-C-S-S-C-) are at 164.0 eV +/-0.5 eV (8 references from ).
There is a lot of confusion in the literature when presenting the data for sulphur. Some papers mention S 2p when they really mean S 2p3/2, these are not interchangeable! Please remember to be specific about the exact peak you are referring to.
 C.D. Wagner, A.V. Naumkin, A. Kraut-Vass, J.W. Allison, C.J. Powell, J.R.Jr. Rumble, NIST Standard Reference Database 20, Version 3.4 (web version) (http:/srdata.nist.gov/xps/) 2003.