The Web Content Accessibility Guidelines 1.0 contains 13 checkpoints that require content developers to create pages in a particular manner "until user agents" support a particular feature. This page documents user agent support for those checkpoints. This page includes additional Resources for User Agent support.
Throughout this document, UAGL refers to the Techniques for User Agent Accessibility Guidelines Working Draft of 6 December 1999. These references will be updated to reflect Techniques for User Agent Accessibility Guidelines 1.0 published December 2002.
Note: As of December 2003, the Web Content Accessibility Guidelines Working Group (WCAG WG) has begun testing and gathering information to update this document.
The test results in this document were last updated 8 December 1999. As of December 2003, we are planning to update the information with test results from the most current versions of Opera, Microsoft Internet Explorer (MSIE), Mozilla, Safari, and Lynx. We also intend to include information about assistive technologies (screen readers, screen magnifiers, and voice input software) that address accessibility requirements.
Tests for the User Agent Support Page was developed in conjunction with this document. However, the more recent Draft Use Agent Accessibility Guidelines test suite for HTML 4.01 will be of more use.
Checkpoint text:
Until user agents can automatically read aloud the text equivalent of a visual track, provide an auditory description of the important information of the visual track of a multimedia presentation.
Status: Under discussion. [link to GL open issues list once added]
Checkpoint text:
Until user agents render text equivalents for client-side image map links, provide redundant text links for each active region of a client-side image map.
Status: Opera 3.6 (Win98) and MSIE 5 (Win98) support tabbing through client-side image maps when the image map image is loaded. Lynx 2.8 (Unix) shows the text equivalents of each image map link as active links.
Len Kasday created a test page and the results are documented on the WAI Interest Group mailing list.
UAGL Techniques for checkpoint 1.1 discuss how user agents should do this.
Checkpoint text:
Until user agents allow users to control flickering, avoid causing the screen to flicker.
Status: Netscape Navigator (versions, platform), Microsoft Internet Explorer (versions, platform), and Opera (versions, platform) allow the user to turn off loading of images, scripts, and applets. Turning these off will allow the user to avoid flicker caused by images, scripts, and applets. For other plug-ins the user can choose not to load the plug-in. However, it would be ideal if users could stop, pause, or step through animations, scripts, or other dynamic content that may cause flicker as discussed in the UAGL checkpoint 3.7 and UAGL checkpoint 3.10
Checkpoint text:
Until user agents allow users to control blinking, avoid causing content to blink (i.e., change presentation at a regular rate, such as turning on and off).
Status: In NN (4.5, Win98) and Opera (3.6, Win98), scripts and style sheets may be turned off separately.They may also be turned off separately with Netscape (4.61, Linux) although turning off scripts has some effect on style sheets. MSIE (5.0, Win98) does not allow the user to turn off style sheets, although user style sheets may override author style sheets. Lynx (2.8, Unix) and Amaya (2.2, Linux) do not support the BLINK element nor style sheets thus no blinking occurs.
Refer to UAGL checkpoint 3.5 and UAGL checkpoint 3.6.
Checkpoint text:
Until user agents allow users to freeze moving content, avoid movement in pages.
No information
Refer to UAGL checkpoint 3.5, UAGL checkpoint 3.6, and UAGL checkpoint 3.10.
Checkpoint text:
Until user agents provide the ability to stop the refresh, do not create periodically auto-refreshing pages.
No information
Refer to UAGL checkpoint 3.10.
Checkpoint text:
Until user agents provide the ability to stop auto-redirect, do not use markup to redirect pages automatically. Instead, configure the server to perform redirects.
No information
Refer to UAGL checkpoint 3.9.
Checkpoint text:
Until user agents allow users to turn off spawned windows, do not cause pop-ups or other windows to appear and do not change the current window without informing the user.
No information
Refer to UAGL checkpoint 4.18.
Checkpoint text:
Until user agents support explicit associations between labels and form controls, for all form controls with implicitly associated labels, ensure that the label is properly positioned.
No information
Refer to UAGL checkpoint 2.1 and UAGL checkpoint 7.4
Checkpoint text:
Until user agents (including assistive technologies) render side-by-side text correctly, provide a linear text alternative (on the current page or some other) for all tables that lay out text in parallel, word-wrapped columns.
Status: IBM's Home Page Reader in combination with Netscape Navigator (4.5, Win98) and Henter Joyce's JAWS in combination with Microsoft Internet Explorer (4.0 and higher, Win98) are instances of a browser and assistive technology combination that can linearize a table. Opera (3.6, Win98) allows a user to linearize tables. Lynx (2.81, Unix) renders tables by row. Silas' Gateway and other tools being developed by the ER Working Group [ER-IG] allow users to linearize tables. However, only Microsoft Internet Explorer (4.0 and higher, Win98) with HelpDB and WWW with EmacsSpeak allow a user to navigate within and between the cells of a table.
Refer to UAGL checkpoint 5.2 and UAGL checkpoint 8.1.
Checkpoint text:
Until user agents handle empty controls correctly, include default, place-holding characters in edit boxes and text areas.
There are two pieces
Refer to UAGL checkpoint 7.4.
Checkpoint text:
Until user agents (including assistive technologies) render adjacent links distinctly, include non-link, printable characters (surrounded by spaces) between adjacent links.
A test case, and some preliminary results are available
Checkpoint text:
Group related links, identify the group (for user agents), and, until user agents do so, provide a way to bypass the group.
No information
The following resources provide information about user agent support for language features (e.g., HTML, CSS) and accessibility features.
W3C provides the information on this page as a service to the Web community and in good faith. However, due to resource constraints, W3C cannot verify the accuracy of all claims made by developers or users. W3C is not responsible for the content or persistence of non-W3C Web sites linked from this page.
Copyright � 1999 W3C (MIT, INRIA, Keio), All Rights Reserved. W3C liability, trademark, document use and software licensing rules apply.