2. Likely GRBs

These transient events are very likely to be cosmic GRBs, but they show some strange features, either in the light curves, resembling background variations, or in the arrival directions, very close to the Sun, or to the Earth direction. Other cases that have been classified as likely GRBs, include those off-line triggers showing typical light curves, but with unusually softer HRs than normal GRBs. On principle, one cannot exclude the possibility that an intermediate HR class of GRBs might indeed exist; on the other hand, since the GRB selection is aimed to extract a conservative catalog of GRBM bursts, these potential GRBs have not been accepted.