Sorting Issues by vBulletin version
Currently users can have VaultWiki installed on a number of different platforms: vBulletin 3.6, 3.8, 4.x and 4.1 w/ ckeditor. With support for XenForo and IPB coming soon, it will become more and more difficult to determine what various issues in the tracker affect if the user doesn't know to say so.
This is useful for speeding up development and solution time, and it would also be useful for users to be able to search for issues that only affect the same platform as them.