Fwd: [css3-background] box-shadow syntax

I've made a diagram that explains my impression of how box-shadow should
work.

http://img440.imageshack.us/img440/5240/shadowdiagramfqh7.png

The first box (top-left) is a red box with a shadow. The shadow is black and
semi-transparent. Now on the second box (mid-left) is a semi-transparent red
box with a shadow, the box is slightly red and is more transparent than the
first. This is because the "light" is transmitted through the box, thus
making the shadow red and less transparent.'

The box on the mid-right has no transmittance and is therefore black, and
normally transparent.

A last thing is the mask setting: if its true: the shadow can't be seen
through the box itself.

Just my thought on how this should work. But of course this is maybe not
they most useful set features, I could see some use of it: If you f.x. had a
..png image with some transparent parts and some solid parts, then you could
make shadows automatically in the UA. That is not possible if the shadow
can't be seen through a semi-/transparent object.

-Henrik