On HTML5 conformance and conformance checking

Currently the HTML5 spec details a number of situations where the alt
attribute is required:

1. "A phrase or paragraph with an alternative graphical representation"

"The text must be given in the alt attribute, and must convey the same
message as the the image specified in the src attribute."

2. "Icons: a short phrase or label with an alternative graphical representation"

"In some cases, the icon is supplemental to a text label conveying the
same meaning. In those cases, the alt attribute must be present but
must be empty."

"In other cases, the icon has no text next to it describing what it
means; the icon is supposed to be self-explanatory. In those cases, an
equivalent textual label must be given in the alt attribute."

"If the logo is being used to represent the entity, the alt attribute
must contain the name of the entity being represented by the logo. The
alt attribute must not contain text like the word "logo", as it is not
the fact that it is a logo that is being conveyed, it's the entity
itself."

"If the logo is being used next to the name of the entity that it
represents, then the logo is supplemental, and its alt attribute must
instead be empty."

3. "A graphical representation of some of the surrounding text"

"In these cases, the alt attribute must be present but its value must
be the empty string."

4."A purely decorative image that doesn't add any information but is
still specific to the surrounding content"

"In these cases, the alt attribute must be present but its value must
be the empty string."

http://www.w3.org/html/wg/html5/#the-img

So wherever these conditions are not met unless

"the alt attribute is only allowed to be omitted when no alternative
text is available and none can be made available, e.g. on automated
image gallery sites."

Documents containing images that have no alt will be not be conforming HTML5.

So while the web may one day contain many documents that get the HTML5
conformance checker "stamp of approval" It will actually be littered
with non conforming HTML5 documents..


-- 
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

Received on Monday, 14 April 2008 14:43:45 UTC