[whatwg] img as a layout tool to describe the displayed region of a CSS background-image

[Ingo Chao]

http://dev.w3.org/html5/spec/Overview.html#the-img-element
"The img must not be used as a layout tool. In particular, img
elements should not be used to display transparent images, as they
rarely convey meaning and rarely add anything useful to the document."

An img with a given transparent image for src cuts an area of a sprite.
( = img as a layout tool to describe the displayed region of a CSS
background-image.)

Is this usage of the img element considered invalid (non-conforming)?

Thanks.

-- 
Ingo Chao
http://www.satzansatz.de/