I quote from ISO/IEC 9594-2:1989
Information Technology - Open Systems Interconnection -
The Directory - Part 2: The Models
"
...
6.1.5 immediate superior (noun): relative to a particular entry
or object (it shall be clear from the context which is intended),
the immediately superior entry or object'
6.1.6 immediately superior
(entry): relative to a particular entry - an entry which is at the
initial vortex of an arc in the DIT whose final vortex is
that of the particular entry;
(object): relative to a particular object - an object whose object
entry is the immediate superior of any of the entries (object
or alias) for the second object
...
6.1.11 subordinate/inferior: the converse of superior
...
6.1.13 superior: (applying to entry or object) immediately superior,
or superior to one which is immediately superior (recursively)
"
... hope this helps ...