A dataset including data elements and order keys for indicating {HEAD ~ an ordering} of {TAIL ~ the data elements} is stored 
of
A dataset including data elements and order keys for indicating { HEAD ~ an ordering } of { TAIL ~ the data elements } is stored
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH