{TAIL ~ System} for exchanging {HEAD ~ data} between a portable payment terminal and a stationary base terminal 
{ TAIL ~ System } for exchanging { HEAD ~ data } between a portable payment terminal and a stationary base terminal
TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH