S1U1B3I1N1D2E1X8
18 points
SUBINDEX is validvalid
a subfix [n SUBINDEXES, SUBINDICES]
a distinguishing symbol written below another character [n SUBINDEXES or SUBINDICES]
a subfix [n SUBINDEXES, SUBINDICES]
a distinguishing symbol written below another character [n SUBINDEXES or SUBINDICES]