checking for trackers that have {TAIL ~ secondary correlations} with one another, according to predefined rules, using {HEAD ~ said frequency value field}, and merging such identified correlated trackers; and 
checking for trackers that have { TAIL ~ secondary correlations } with one another , according to predefined rules , using { HEAD ~ said frequency value field } , and merging such identified correlated trackers ; and
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH