>>33044847USUM, but that's shorthand, and nobody pronounces abbreviations like they're spelled. At the worst, I'll just say the letters out loud, but saying the actual words ("HeartGold and SoulSilver" vs "Aych-Jee-Ess-Ess") doesn't make you sound like an asshole.
RG - Red and Green
Blue
Pikachu/Yellow
GS - Gold and Silver
Crystal (GSC when included with Gold and Silver)
RS - Ruby and Sapphire
FRLG - FireRed and LeafGreen
Emerald (RSE when included with Ruby and Sapphire)
DP - Diamond and Pearl
Platinum (DPPt when included with Diamond and Pearl)
HGSS - HeartGold and SoulSilver
BW - Black and White
B2W2 - Black 2 and White 2
XY - X and Y
ORAS - Omega Ruby and Alpha Sapphire
SM - Sun and Moon
USUM - Ultra Sun and Ultra Moon
These are also the abbreviations used officially in Japan. Abbreviations are basically just the capitalized letters and numbers (if present). Platinum has an added lowercase "t" to differentiate it from Pearl, and I've seen that done in Japanese, Korean, and English. I refer to Red, Green, Blue, and Pikachu/Yellow as Gen I collectively because I'm an accuracyfag and call the last Gen I game "Pikachu" like it's called in Japan instead of "Yellow" and I don't want to deal with people questioning it.
Red, Ruby, FireRed, Omega Ruby (R, R, FR, OR) - doesn't work, but doesn't matter
Green, Gold, LeafGreen, HeartGold (G, G, LG, HG) - doesn't work, but doesn't matter
Silver, Sapphire, SoulSilver, Alpha Sapphire, Sun, Ultra Sun (S, S, SS, AS, S, US) - doesn't work, but doesn't matter
Pearl, Platinum (P, P) - doesn't work, matters, hence the Pt
Black, Black 2 (B, B2) - works
White, White 2 (W, W2) - works
Moon, Ultra Moon (M, UM) - works
