Help, About the data
How Tana decides where a game was released
Tana only catalogues physical games. Download-only releases aren't included, though Tana does note when Japan only got a game as a download (that's the Physical in the West only stamp).
Before a game is added as Japan only or Western only, Tana looks for evidence that it really came out physically in that region, i.e. a retail release list, a disc or cartridge serial, or a store catalogue entry. Each platform family uses the sources that work best for it.
When the evidence isn't there, the game is held back instead of guessed. That's why a few games may be missing for now. If you know one of them, add it or leave a comment.