a registration unit that, when receiving a print request from any one of {TAIL ~ the plurality} of host computers, registers host information indicative of the host computer as a source of the request so that {HEAD ~ an order} of print requests can be identified 
a registration unit that , when receiving a print request from any one of { TAIL ~ the plurality } of host computers , registers host information indicative of the host computer as a source of the request so that { HEAD ~ an order } of print requests can be identified
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL 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 HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH