DVD-9 is a legit type. I have several DVDs I KNOW are legit and they're DVd-9, including my Mei-Ah copy of 2046.

I've seen pirates copies in mainland China where they put DVD-9, DVD-5, VCD, and some other conflicting stuff altogether on the back of the box. Those were hilarious. Doesn't really bother me too much since they're ovious pirates, but they also list languages that aren't on the DVD. That's just going too far.