Next, the client identifies {HEAD ~ a record} and instructs {TAIL ~ the verification system} to retrieve the record 
Next , the client identifies { HEAD ~ a record } and instructs { TAIL ~ the verification system } to retrieve the record
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH