Let’s say you want to use a <header> tag for the header part of your site.
But currently your header is made from 3 elements (because of design-related reasons), like:
<div id="header-wrap">
<div id="header">
<div id="header-content">
...
</div>
</div>
</div>
So which one of these DIVs should be replaced with <header> ? And does it matter?
A purpose of HTML5’s new tags is to add semantic meaning to your document. On the other hand, generic elements like
<div>have been preserved precisely because they have no semantic meaning. They are ideal for adding visual structure without impacting the semantic structure.The
<header>element should envelop the semantic header. I would venture to say it’s most likely the outermost element that should be<header>since all elements involved clearly exist to support the header in some fashion, but only you know the semantic meaning of your document best, so you can best answer specifically.