The grouping keyed on the callsign alone, so every spot of a station outside the
first one's band and mode was dropped from the list. RI1FJL spotted on 17m CW,
20m, 30m, 12m and 15m FT8 showed as a single row: four slots gone from the one
view an operator uses to find them.
A duplicate is the dozen skimmers that all heard the same CQ — same station,
same band, same mode. The same station on another band is the opposite of a
duplicate; it is what the chaser is scanning for.