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Improving Accessibility With HTML 4.0

Enabling the Web for People with Disabilities

By Mike Paciello

If you've read any of my "Web Enabled" articles in Web Techniques, you'll appreciate my exaltation with the recent release of the HTML 4.0 specification by the World Wide Web Consortium (W3C). The HTML 4.0 specification includes, among other things, increased accessibility enhancements for people with disabilities. New rules, attributes, and elements have been defined to enrich HTML so that Web content will become more available to a broader audience.

Additionally, the proposal for the next Cascading Style Sheet (CSS2) specification includes the Aural Cascading Style Sheet (ACSS). Using ACSS, blind and print-impaired users can render Web content audibly without losing document structure, therefore increasing overall comprehension. For example, the visual structure of a mathematical expression is often important to understanding the equation.

Indeed, there's more material to cover than space permits, so I'll save a discussion of ACSS and its advantages for people with disabilities for another time. In this article, I'll give a summary of changes included within the HTML 4.0 specification, then focus on enhancements involving structured elements and attributes as well as images, image links, text links, forms, and a few style issues.

Summary of Changes

When it comes to accessibility, the HTML 4.0 specification provides for:

• Better distinction between document structure and presentation, thus encouraging the use of style sheets instead of HTML presentation elements and attributes;
• Better forms, including the addition of access keys and active labels, and the ability to group form controls and select options semantically;
• The ability to mark up a text description of an included object (with the OBJECT element);
• A new client-side image map mechanism (the MAP element) that lets authors integrate image and text links;

The requirement that alternate text accompany an image included via the IMG element;

• Support for the title and lang attributes on all elements;
• Support for the ABBR and ACRONYM elements;
• A wider range of target media (TTY, braille, and so on) for use with style sheets;
• Better tables, including captions, column groups, and mechanisms to facilitate nonvisual rendering;
• Long descriptions of tables, images, frames, and so on.<>