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