Each zone may store instant messaging information for a subset of the peers at locations in the zone indicated by {TAIL ~ hashes} of identifiers of the peers in {HEAD ~ the instant messaging group} 
Each zone may store instant messaging information for a subset of the peers at locations in the zone indicated by { TAIL ~ hashes } of identifiers of the peers in { HEAD ~ the instant messaging group }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD