  Theoretical and observational evidences have been recently gained for a
two-fold classification of short bursts: 1) short gamma-ray flashes (S-GRFs),
with isotropic energy $E_{iso}<10^{52}$~erg and no BH formation, and 2) the
authentic short gamma-ray bursts (S-GRBs), with isotropic energy
$E_{iso}>10^{52}$~erg evidencing a BH formation in the binary neutron star
merging process. The signature for the BH formation consists in the on-set of
the high energy ($0.1$--$100$~GeV) emission, coeval to the prompt emission, in
all S-GRBs. No GeV emission is expected nor observed in the S-GRFs. In this
paper we present two additional S-GRBs, GRB 081024B and GRB 140402A, following
the already identified S-GRBs, i.e., GRB 090227B, GRB 090510 and GRB 140619B.
We also return on the absence of the GeV emission of the S-GRB 090227B, at an
angle of $71^{\rm{o}}$ from the \textit{Fermi}-LAT boresight. All the correctly
identified S-GRBs correlate to the high energy emission, implying no
significant presence of beaming in the GeV emission. The existence of a common
power-law behavior in the GeV luminosities, following the BH formation, when
measured in the source rest-frame, points to a commonality in the mass and spin
of the newly-formed BH in all S-GRBs.
