You need to read "b"'s post again.

Here in Americaland, HD is only HD if it meets a minimum of 720 vertical lines, anything bellow that cannot be considered HD. The 720x480 or 576 is Standard Definition. I imagine it's the same across the pond.

HD, HD, HD

SD(Standard Definition), or D1 as it is also called, is 720x576 -at least here in eurodisney, in disney proper it is 720x480.

But you already knew that. Anything below SD is LD(Low Definition) -I just made that up, but it seemed logical. Thus the new youtube HD is actually LD, as opposed to CD(Crap Definition). I just made that up too.

It's just like that dating section on MAD TV, the title of which I tend to sing to myself ever more often: Lowered Expectations.

b