An enforcement mechanism uses the access rights set up for {TAIL ~ the user} to determine whether to grant or deny {HEAD ~ accesses} to resources 
An enforcement mechanism uses the access rights set up for { TAIL ~ the user } to determine whether to grant or deny { HEAD ~ accesses } to resources
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH