A communication data set together with the data trace is stored as {TAIL ~ a data set} that is retrievable by {HEAD ~ authorized persons} 
A communication data set together with the data trace is stored as { TAIL ~ a data set } that is retrievable by { HEAD ~ authorized persons }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD