receiving at a host computer system including a processor, from {TAIL ~ each} of a plurality of payment processing organizations, a set of security requirements defining protocols for implementing commercial transactions over the shared network using instruments identified with {HEAD ~ the payment processing organization} 
receiving at a host computer system including a processor , from { TAIL ~ each } of a plurality of payment processing organizations , a set of security requirements defining protocols for implementing commercial transactions over the shared network using instruments identified with { HEAD ~ the payment processing organization }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH 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 HEAD