Well, to be clear, "supposed to" doesn't necessarily line up with reality. Accounting for blanking makes little sense in a world where DVD's are expected to be played back over all-digital connections, so modern DVDs frequently go right to the edges. But older discs tend to put some room for blanking on the sides, and that seems to include the GOUT. If there's usable image within the blanking area, you're free to decide what you want done with it, as long as you maintain the right aspect ratio. I tend to just chop it, because it was designed for that to happen.