{TAIL ~ This request} may be originated by the user, by {HEAD ~ the system operator}, or by the subscriber identity module 
{ TAIL ~ This request } may be originated by the user , by { HEAD ~ the system operator } , or by the subscriber identity module
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH