[css3-background] background-clip: content-box

We added a 'content-box' value to 'background-clip' to make it
parallel with 'background-origin', since in the 'background'
shorthand the 'border-box' and 'padding-box' will set both.

But I can't imagine any use for it. I can see wanting to position
images relative to the content box. But I can't see wanting to
clip background images to the content box.

Should this value be removed? That would mean
   background: url(image.src) top left content-box;
will place an image in the top left corner of the content box,
but clip to the border-box (background-clip's default).

It could be useful for something like
   background: url(flower.src) -10px -10px content-box no-repeat;
   /* Place a flower over the top right corner of the first letter */
I can imagine a lot more reasons to want to position to the content
box and clip to the border box than wanting to clip to the content
box.

~fantasai