[whatwg] W3C compatibility

Mon Feb 12 06:01:10 PST 2007

Henri Sivonen wrote:

> What's there in XHTML5 that would require breaking XHTML1 support (in  
> practice, predefined class names don't break practice)?

That depends on whether any behaviour/presentation is specified for
class names.

Any AT or talking browser relying on <abbr> vs <acronym> as a
pronunciation guideline is going to be broken by XHTML5's ditching of
<acronym>:

http://www.sidar.org/funacti/inves/resul.php

Likewise, any document mapping using <h1> to <h6> to build hierarchies
in a simple manner is going to be thrown by XHTML5's reuse of such
headings for subtitles and by markup like:

<body>
 <h4>Apples</h4>
 <p>Apples are fruit.</p>
 <section>
  <h2>Taste</h2>
  <p>They taste lovely.</p>
  <h6>Sweet</h6>
  <p>Red apples are sweeter than green ones.</p>
  <h1>Color</h1>
  <p>Apples come in various colors.</p>
 </section>
</body>

to use an example out of the spec.

--
Benjamin Hawkes-Lewis