General Use == not Authoring
Virtually all DVD-Rs are G.U. You need special drives to use Authoring discs, and Authoring discs are very expensive and hard to find. Generally, only professional video production houses and movie studios use Authoring drives and Authoring discs (because you can record region control and CSS information on Authoring discs). It's almost like how most people don't pay attention to the "unleaded gas only" sticker because all the normal gas out there is unleaded.