Dropped Item appears in 2 version groups since Generation V, an Unused item in the Key Items pocket
PokéAPI item 926 of 2,223, Unused category, Key Items pocket
Effect, in PokéAPI's words
Dropped Item: “XXX new effect for dropped-item--red”
Games
Dropped Item is listed in the text of 2 version groups, first in Generation V
Game index by generation
IIIIIIIVVVIVIIVIIIIX
Named in
Ultra Sun and Ultra MoonLet's Go Pikachu and Let's Go Eevee