The remaining "???"s are mostly new to Crystal (mobile-related):
audio/engine.asm:2208: ; add ??? to the next result
audio/engine.asm:2217: ; store result in ???
audio/engine.asm:2286: ; clear ???
data/battle_tower/unknown.asm:1:BattleTowerTrainerData:: ; ???
data/player_names.asm:6: db 0 ; ???
data/player_names.asm:25: db 0 ; ???
engine/events/battle_tower/battle_tower.asm:1387: ld a, 0 ; ???
engine/menus/init_gender.asm:14: res 0, a ; ???
engine/menus/init_gender.asm:17: res 1, a ; ???
lib/mobile/main.asm:8528: cp $8e ; LOW(MD5_K_Table + $100) ???
mobile/mobile_40.asm:242: ret ; ???
mobile/mobile_41.asm:1034: ld b, $0f ; no graphics at 0f:40b0; JP leftover???
mobile/mobile_46.asm:1972: ld a, $3 ; ???
mobile/mobile_46.asm:2501: ld a, $6 ; ???
Corresponds to https://github.com/pret/pokegold/pull/116
The remaining "???"s are mostly new to Crystal (mobile-related):