a kind of package selecting means of selectively specifying {HEAD ~ the kind} of {TAIL ~ packages} to be packaged 
of
a kind of package selecting means of selectively specifying { HEAD ~ the kind } of { TAIL ~ packages } to be packaged
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH