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