Since we have a dumping standard that everyone uses (or should use), we are then able to differentiate between different versions of the same games with in the same region via the difference in the CRC32/MD5 values.
I doubt there would be any but I was wondering if there was any online resources that actually state the in-game differences between different versions of the same game? I'll also accept Japanese websites (preferred, since I'm mainly looking for Japan-region game info) that has relevant related info. Since Japan is very... thorough when it comes to gaming, perhaps even a published book (doubtful but eh...).
Perhaps we can even theorise on how to find out such a thing.
These differences could be anything from bug fixes ("Blue Reload/Red Reload" versions of PS2 Guilty Gear XX), gameplay tweaks (Ultimate Hits/Front Mission History PS1 versions of Front Mission 2), minor extra content (PlayStation the Best/PSOne Books PS1 versions of Akumajou Dracula X: Gekka no Yasoukyoku) and even significant bonus content/material (Greatest Hits/Platinum PS2 versions of Silent Hill 2).
I suppose regional differences might also fall under this category but these are more obvious and more well-known. I'm mainly interested in same-region same-game different-version differences.
i.e. Alundra Japan-to-USA: Added usage of shoulder buttons to bring up menus, enemies take twice as long to kill (but same difficulty).
i.e. Suikoden 2 USA-to-Europe: Fixed "McDohl" naming bug/corruption, other noticable bugs also fixed such as characters singing instead of complete silence.
and etc...