using the data* attribute to identify element sub roles

NOTE: this is just a wild idea.

allow the data attribute [1] to be used to identify element sub roles:

examples:

<h1>heading</h1>
<p data-p="subheading">subheading</p>


<article data-article="comment"> blog post comment </article>


allow data-elementname="subRole" pairs to be added to a public registry.

thoughts?

[1]
http://www.w3.org/html/wg/drafts/html/master/dom.html#embedding-custom-non-visible-data-with-the-data-*-attributes


-- 
with regards

Steve Faulkner