I'll probably just confuse the matter, but perhaps we need to alter the region designation. I've been brought up on PAL systems and NTSC imports, and those are the two classic differentiators (Rather than EU and NA).
For contemporary systems (I'm so old, I'd include the SNES onwards) Perhaps changing the main regions to:
EU -> PAL
JP -> NTSC-J
NA -> NTSC-US or NTSC-U/C
Then, designating a subregion (i.e. a country or continent) within the game details itself. I've discovered some differences between identical regions from different countries.
[PAL]
-Europe-
* Specific Ratings (Superseded by PEGI, but different EU countries had their own before, so this could be useful for older titles)
*Localisation
*Country exclusive releases (e.g. PAL Rule of Rose only from France, God of War 3 digipak edition from Amazon.de)
-Australia-
*Specific Ratings (FUGLY ones, too)
-Middle East-
Big retail chains in Qatar, UAE, Saudi Arabia and Bahrain seem to mainly deal with PAL distribution of PEGI or USK rated games, however there are:
*Some custom Arabic covers, despite european rating
*Store exclusives availability, e.g. recent MW3 steelbook collection promotion at Dubai Virgin Megastore (with Dogtags to win a Hummer!). Some PAL store/country/publisher exclusives are on general release here as well. Well chuffed to find a mint, sealed ICO digipak case edition here in Saudi.
[NTSC-J]
-South Korea-
Different from JAPAN !
*Custom covers and perhaps localisation (language) for both PS3 and XBox360 games. Got a copy of Crackdown with Japan's "Riot Act" artwork, but rest of the world's "Crackdown" title, from a store in SAUDI ARABIA no less. Apparently this was the Korean version, but clearly showed NTSC-J.
*Some Xbox360 NTSC-J's /NOT/ from Japan are not region locked.
This is going to crowd the list, but maybe instead of having a drop down list, could region selection not work like publishers (i.e. start typing, and a verified selection can be made). Now I know, most uses here are probably in North America and could not care less, but for collectors from elsewhere, being able to differentiate would be useful.