[html4all] Numbered headings (was HTMLWG)

Mon Nov 26 08:20:54 PST 2007

Hi Lachlan,

> Please describe how this change could adversely affect legacy pages
This would not affect legacy pages. This will affect legacy tools. For example, an accessibility checker tool or markup validator reports to users on incorrect use of headings. Currently it will report two errors in the following markup:

<h3></h3>
<h1></h1>
<h6></h6>

Error 1: lower value heading precedes higher value heading

Error 2: headings skipped

Now, if someone is writing an X/HTML 5 Web page, the previous markup is valid but the user will still get an error message in the accessibility validator built into their legacy authoring tool.

This is why changing the semantics of h1 to h6 is not backwards compatible.

Regards,
-Vlad
http://xhtml.com

-------- Original Message --------
From: Lachlan Hunt
Date: 2007-11-26 11:01 AM
> Vlad Alexander (XStandard) wrote:
>> 2. Redefining the semantic meaning of h1 is not backwards compatible.
> 
> Please describe how this change could adversely affect legacy pages, 
> given that the alorithm is explicitly defined to deal with current usage 
> of h1-h6 as well as when they are nested within section elements.
> 
>> 4. And more precisely, the X/HTML 5 spec does not in fact treat
>> section/h1 as equivalent to the XHTML 2 section/h construct as
>> illustrated by this example from X/HTML 5:
>>
>> <body>
>>  <h1>Apples</h1>
>>  <p>Apples are fruit.</p>
>>  <section>
>>   <h2>Taste</h2>
>>   <p>They taste lovely.</p>
>>   <section>
>>    <h3>Sweet</h3>
>>    <p>Red apples are sweeter than green ones.</p>
>>   </section>
>>  </section>
>>  <section>
>>   <h2>Color</h2>
>>   <p>Apples come in various colors.</p>
>>  </section>
>> </body>
> 
> I do not understand how that markup illustrates your point.  HTML5 
> allows the h2-h6 elements to be used within nested sections in place of 
> h1 elements so that authors may achieve better compatibility with 
> current browsers.  The heading structure for that would be semantically 
> identical to the equivalent markup using all h1 elements instead.
> 