It annoys me so fucking much.
People need to understand that 4 letters names are reserved to remakes.
Red/Blue -> RB
FireRed/LeafGeeen -> FRLF
Gold/Silver -> GS
Heartgold/Soulsilver -> HGSS
Ruby/Sapphire -> RS
Omega Ruby/Alpha Sapphire -> ORAS
Sun and Moon are not remakes so they must be called SM, not SUMO