These guidelines are intended to help facilitate the design of web pages that are accessible to people with disabilities. Special attention should be paid to the construction of web pages so that they can be easily "viewed" by people using computer software and equipment such as screen readers, Braille output devices, or non-standard input devices. This document provides information on some of the commonly used tags that enable web pages to be accessed by people with hearing and visual disabilities. There is also a list of links to sites with more detailed information and the full text of the World Wide Web Consortium Initiatives on this subject.
The World Wide Web Consortium (W3C) has created a set of guidelines to help web authors create web pages that make the Internet accessible to all. ITS encourages web authors to design pages that meet the minimum standards set forth in the W3C Web Accessibility Initiatives. The most critical design considerations can be summarized as follows:
- Provide alternate text for all images and image maps in your document.
- The same alt syntax can be used in client-side image maps to provide alternate text for each link area in the image. Be sure that the text provides an adequate description of the link's target for a user who may be relying on a screen reader or other assistive technology to read the page.
- Identify row and column headers in tables. The HTML 4.0 table tags allow data to be associated with a specific header and for multiple columns to be grouped together. If you are creating complex tables in HTML, it is advisable to consult an HTML 4.0 reference book and the W3C guidelines for advice on how to create accessible data tables. Note that the W3C recommends that the use of tables purely for screen formatting be kept to a minimum.
- If you use Cascading Style Sheets in your page, be sure that the page organization will still be coherent when it is viewed by a browser or screen reader that does not support CSS.
- Be sure that the text and background colors provide sufficient contrast. Consider that color-blind readers may have difficulty distinguishing text and background colors.
- Provide titles for each document frame in a frame set.
- Provide text descriptions for all multimedia content, scripts, ASCII art, images used as list bullets, spacers, graphical buttons, sounds (played with or without user interaction), stand-alone audio files, audio tracks of video, and video.
- Do not cause the screen to flicker.
- If all else fails, present the user with the option to view a text-only page.