maintaining the package identifier in a protected manner such that the package identifier is accessible to an operating system of the device but not accessible to {HEAD ~ other applications} of {TAIL ~ the device} 
maintaining the package identifier in a protected manner such that the package identifier is accessible to an operating system of the device but not accessible to { HEAD ~ other applications } of { TAIL ~ the device }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL