Lars asked:
All <article>s are <section>s but not all <section>s are <article>s
Just to be clear: Does that include the rules for headers when
articles are nested, or when an article is contained in a section?
Yes, the content model is identical. They are both sectioning content.
E.g. would this structure be treated as an identical flow from a
headings level perspective if all article tags where replaced with
section tags? I.e. Would it be as if I'd use h1, h2 and h3 today?
<section>
<h1 />
<article>
<h1 />
...
<article>
<h1 />
</article>
</article>
</section>
Yes. From an outline point of view, this is identical:
<section>
<h1 />
<section>
<h1 />
...
<section>
<h1 />
</section>
</section>
</section>
As is this:
<article>
<h1 />
<article>
<h1 />
...
<article>
<h1 />
</article>
</article>
</article>
--
Jeremy Keith
a d a c t i o
http://adactio.com/
