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