The purpose of the "role" attribute I see on the theme files.

Question

What is the purpose of the "role" attribute in the WP themes?

For example, in the WP3 default theme we have this in footer.php

I searched for the string "contentinfo" and found that this is the only occurrence in the default theme folder.

What's it's purpose? How is it used?

Answer 1

role is an XHTML attribute used to identify the context of elements on the page. The search bar will also render with role="search" on a WordPress site.

You can read more about it at the W3C specification site.

To answer your specific question, role="contentinfo" identifies "Meta information about the content on the page or the page as a whole."

The role attribute itself can be used by other applications (i.e. screen readers) to determine the purpose of the elements on the page. It gives things a stronger meaning than the explicit names we use for element IDs (which aren't codified in any way).

Answer 2

It is also part of the WAI-ARIA specification (Accessible Rich Internet Applications)

You can also read about it on the W3C Specifications site