What? "High Quality" doesn't mean anything at all. It's subjective, not boolean.
1080p is often referred to as "Full HD" in marketing. The point is, they're both HDTV formats and there's no other official notation.
Yes, but having hd for both 720 p and 1080 p would seem that there wouldnt be a difference.
HQ distinguishes HD which should only be used for perfect clarity and of course companies use hd for 720 p just to fool unsuspecting customers.