HTML and CSS Reference
for authors to use the native feature and stop using WAI-ARIA
for that feature.”
So something like HTML5 <nav> shouldn't need ARIA role=
navigation added to it, because it should (in an ideal world)
have that built-in. However, HTML5 is very new, whereas ARIA
already has some support in assistive technology. So it shouldn't
hurt to use the built-in element plus the ARIA information, and
it can only help users who rely on assistive technology. The
HTML5 validator at html5.validator.nu therefore validates ARIA
as well as HTML5 (whereas HTML 4 validators report ARIA infor-
mation as an error because HTML 4 predates ARIA).
ARIA document structure
and landmark roles
WAI-ARIA defines several roles that tell assistive technology
about landmarks and structure of a document. Some of these are:
Looking at a simple page from an ARIA perspective, you might
see what is shown in Figure 2.18 .
FIGURE 2.18 A simple page
with a header, sidebar, and main
content area and ARIA roles.