Re: ARIA roles added to the a element should be conforming in HTML5.

On Sun, Nov 8, 2009 at 2:13 AM, Maciej Stachowiak <mjs@apple.com> wrote:
> Bespin is in fact not valid HTML5, but for another reason. HTML5 says: "When
> authors use the canvas element, they must also provide content that, when
> presented to the user, conveys essentially the same function or purpose as
> the bitmap canvas." Thus, Bespin is nonconforming because it fails to
> provide fallback that conveys the same function.

Isn't that an unrealistically strict requirement?  Is such a
requirement made for any other feature?  Pages aren't required to
support clients that don't support JavaScript, or CSS, or SVG, are
they?  Even the requirement of fallback for <img> is qualified -- you
can provide empty alt text if it's purely decorative, and are only
required to provide best-effort alt text if conveying essentially the
same function as the image is impractical (e.g., the image is too
complicated).