A SIM server provides access to the SIMs, {HEAD ~ a SIM librarian} catalogs {TAIL ~ the SIMs}, and a SIM accounting system tracks and/bills for SIM usage 
A SIM server provides access to the SIMs , { HEAD ~ a SIM librarian } catalogs { TAIL ~ the SIMs } , and a SIM accounting system tracks and / bills for SIM usage
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH