I think other categories for covers aside from Region-localization should be added.

Such as whether it's Digital or Physical (since game covers can differ between a physical box or the digital gamestore, i.e. PSN/xbox store/etc, even though it seems to be a fairly rare occurence).

Maybe even being able to say what console(s) a specific cover is for, which is helpful for some cases, such as games that might have different covers for re-releases across different generations of platforms (which also seems rare, but it does happen, i.e. the Devil May Cry HD collection has different covers for its ps3/xbox360 and ps4/xboxone releases).

A hypothetical localization or cover submission could be:

Region: Japan
Localized Title: デビル メイ クライ トリプル パック
Cover Medium: Physical
Console(s): Playstation 3, Xbox 360