clarification on normative and informative

Hi Ian, I am working on an action item [draft text for HTML 5 spec to
require producers/authors to include @alt on img elements -
http://www.w3.org/html/wg/tracker/actions/54] in regards to current HTML5
draft specification img section [http://www.w3.org/html/wg/html5/#the-img].

I have read the section of the spec in relation to normative/informative,
but it is still unlcear to me. Can you clarify what parts of the img section
are normative and which are informative:

for example:

"A graphical representation of some of the surrounding text

In many cases, the image is actually just supplementary, and its presence
merely reinforces the surrounding text. In these cases, the
alt<http://www.w3.org/html/wg/html5/#alt>attribute must be present but
its value must be the empty string."

Is the above normative or informative? or a mixture?
and this example:

"The img <http://www.w3.org/html/wg/html5/#img> must not be used as a layout
tool. In particular, img <http://www.w3.org/html/wg/html5/#img> elements
should not be used to display fully transparent images, as they rarely
convey meaning and rarely add anything useful to the document. "

thanks for your help on this.

-- 
with regards

Steve Faulkner
Technical Director - TPG Europe
Director - Web Accessibility Tools Consortium

www.paciellogroup.com | www.wat-c.org
Web Accessibility Toolbar -
http://www.paciellogroup.com/resources/wat-ie-about.html