An information database in {HEAD ~ communication} with {TAIL ~ an information application} comprises a plurality of marketplaces and a plurality of listings respectively classified within the plurality of marketplaces 
with
An information database in { HEAD ~ communication } with { TAIL ~ an information application } comprises a plurality of marketplaces and a plurality of listings respectively classified within the plurality of marketplaces
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH