A page must have exactly one element with role="main"

Rationale

The WAI-ARIA main landmark role can be help keyboard users with assistive technologies such as screen readers (and in the future as native browser functionality) to skip directly to the main content of a page, bypassing navigation and other contents that might be before it.

Techniques

Pass:

<div role="main" id="main-content"></div>

Fail:

<div id="main-content"></div>

Tests