<div><p>I'd like to suggest adding the Product Code as a property under Video Game Version (/cvg/game_version).
I suggest this since it's the only truly unique identifier for each video game version and is only re-used (to my knowledge) in the case of a game being changed from the standard title to a greatest hits title (title is physically repackaged but keeps all of the title properties as the original).</p>
<p>For example 007 Racing for the PlayStation has the following versions:</p>
<p>Title, Publisher, Product Code, Release Date, Region
007 Racing  Electronic Arts SLUS-01300  11/20/00    US
007 Racing  Electronic Arts SLES-03355  12/15/00    EU
007 Racing (Platinum)   Electronic Arts SLES-03355/P    09/21/01    EU</p></div>