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