Positive tabindex attribute values must not be used to create a logical tab order.

tabindex values of 0 must not be used on elements that are not focusable by default.

Rationale

Typical BBC pages are made up of several shared components (Global navigation, page content, share tools, location service widgets, etc.) so no one piece of code has complete awareness of the content of the page or when the content updates. Positive tabindex values results in unpredictable tab order that do not occur if the natural order of content is relied upon.

Using tabindex="0" on an element adds it to the document tab order, however it does not change the element type to allow it to be discovered by navigating by link or form element, nor does it bind click and key press handlers to the element. There are no circumstances in which it is not better to use a natively focusable control such as a <a> or<button>.

Techniques

Pass:

<a href="/news">News</a>

<button type="submit">Search</button>

<div tabindex="-1"></div>

Fail:

<a href="/news" tabindex="1">

<button type="submit" tabindex="2">Search</button>

<div tabindex="3"></div>

<div tabindex="0"></div>

Tests