SIMBAD query result

Please have a look at the "Dictionary of Nomenclature"

Result of query: info cati KMT-2018-BLG-1990L

.

 [Class]      Acronym  (Explanation)   . . . . . . . . . in Simbad, use:
 [LensingEv]  KMT (Korea Microlensing Telescope Network)  KMT -YYYY-{BLG}-NNNN
                                                       or KMT -YYYY-{BLG}-NNNNa
                                                       or KMT -YYYY-{BLG}-NNNN{L} (L)
                                                       or KMT -YYYY-{BLG}-NNNN{L}a (L)
(L) following the Usage indicates a 'format' found later in the literature,
    which is not recognized by SIMBAD.