A tree structure resembling the packaging hierarchy is disclosed, where the nodes are referenced by the unique reference, and {HEAD ~ tracing} of {TAIL ~ entire sub trees} may be performed by entering a unique code 
of
A tree structure resembling the packaging hierarchy is disclosed , where the nodes are referenced by the unique reference , and { HEAD ~ tracing } of { TAIL ~ entire sub trees } may be performed by entering a unique code
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH 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