A process token can optionally have {HEAD ~ multiple additional types} of {TAIL ~ SIDs} based on other criteria  
of
A process token can optionally have { HEAD ~ multiple additional types } of { TAIL ~ SIDs } based on other criteria
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH