Let
be
. The unitary dual
was classified by
Vogan in the 1980s. This paper aims to describe the Zhelobenko parameters and the spin-lowest
-types of the scattered
representations of
, which
lie at the heart of
—the
set of all the equivalence classes of irreducible unitary representations of
with
nonvanishing Dirac cohomology. As a consequence, we will verify a couple of conjectures of
Dong for
.