Technologies that contain focusable elements
This technique relates to:
Operating systems have a native indication of focus, which is available in many user agents. The default rendering of the focus indicator isn't always highly visible and may even be difficult to see against certain backgrounds. However, many platforms allow the user to customize the rendering of this focus indicator. Assistive technology can also change the appearance of the native focus indicator. If you use the native focus indicator, any system-wide settings for its visibility will carry over to the Web page. If you draw your own focus indicator, for example by coloring sections of the page in response to user action, these settings will not carry over, and AT will not usually be able to find your focus indicator.
The default focus indicator on Microsoft Windows is a one-pixel, black dotted line around the focused element. On a page with a dark background, this can be very difficult to see. The creator of the page uses the default, and the user customizes it in Windows to make it a bright color.
In HTML, form elements and links can be focused by default. In addition, any element with a tabindex attribute >= 0 can take focus. Both types of focused elements use the system focus indicator and will pick up platform changes in the focus indicator style.
Use the features of your platform to customize the appearance of the focus indicator
Tab through the page, noting the path of the focus
Check that the focus indicator for each control is visible
Check #3 is true
If this is a sufficient technique for a success criterion, failing this test procedure does not necessarily mean that the success criterion has not been satisfied in some other way, only that this technique has not been successfully implemented and can not be used to claim conformance.
Techniques are informative—that means they are not required. The basis for determining conformance to WCAG 2.0 is the success criteria from the WCAG 2.0 standard—not the techniques. For important information about techniques, please see the Understanding Techniques for WCAG Success Criteria section of Understanding WCAG 2.0.