{HEAD ~ The user affinity groups} may be formed by comparing {TAIL ~ user profiles} with each other or with a predefined affinity group profile definition 
formed by comparing
{ HEAD ~ The user affinity groups } may be formed by comparing { TAIL ~ user profiles } with each other or with a predefined affinity group profile definition
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH