storing {HEAD ~ the protection level} of {TAIL ~ each} of the set of data stored in the leaf nodes; and 
of
storing { HEAD ~ the protection level } of { TAIL ~ each } of the set of data stored in the leaf nodes ; and
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH