accept data received from the first data enterer into the system if the data are entered in a format compliant with {HEAD ~ a first set} of {TAIL ~ rules} 
of
accept data received from the first data enterer into the system if the data are entered in a format compliant with { HEAD ~ a first set } of { TAIL ~ rules }
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 HEAD REL TAIL TAIL TAIL TAIL TAIL