1. Assign ALT Descriptions to Images
Screen readers, which are used by many visually impaired Web users, can't understand images. To ensure accessibility, an alternative description needs to be assigned to every image; the screen reader will read out this alternative, or ALT, description:

2. Display Text Through HTML, Not Images
Text embedded in images appears pixelated, blurry, and is often unreadable by those who use screen magnifiers. From an accessibility point of view, text embedded in images should therefore be avoided.

3. Use Descriptive Link Text
Visually impaired Web users can scan Web pages by tabbing from link to link, listening to the content of the link text as they go. As such, the link text in an accessible Website must always be descriptive of its destination.

4. Website Functions with JavaScript Disabled
JavaScript is unsupported by about 7% of Web users, either because they've turned it off (perhaps to prevent pop-up adverts) or because their browser doesn't support it. Many forms of JavaScript aren't accessible to those who use screen readers.

5. Alternatives to Flash-Based Content Provided
Like JavaScript, Flash isn't accessible to many users, including those using screen readers. Equally, few search engines can access Flash -- be sure to provide equivalents.

6. Transcripts Available for Audio
Hearing impaired users obviously require written equivalents for audio content in order to access that information.
Typically, search engines are also unable to access audio content; transcripts provide them relevant text to index.

7. Site Map Provided
Site maps can be a useful tool for visually impaired users as they provide a straightforward list of links to the main pages on the site.

8. Meaningful Page Title
When we arrive at Web pages, the first thing that appears -- the first thing that visually impaired users hear -- is the page title. Visually impaired Web users don't have the privilege of being able to quickly scan the page to see if it contains the information they're after, so it's essential that the page title effectively describes the page content.

9. Headings and Sub-Headings Used
Visually impaired Web users can scan Web pages by tabbing from heading to heading, as well as from link to link (see point 3 above). As such, it's important from an accessibility standpoint to make sure your headings are correctly marked up using <h1>, <h2>, etc. tags.

10. CSS Used for Layout
Screen readers can more effectively work through the HTML code of CSS-based sites as there's a greater ratio of content to code. Websites using CSS for layout can also be made accessible to in-car browsers, WebTV and PDAs. As I mentioned in the first part of this article, it's estimated that 58 million PDAs will be sold worldwide in 2008.

Secret Benefits of Accessibility Part 1: Increased Usability
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1. Descriptive Link Text
Visually impaired Web users can scan Web pages by tabbing from link to link and listening to the content of the link text. As such, the link text in an accessible Website must always be descriptive of its destination.

2. Descriptive Form Labels

3. Divide Large Chunks of Information
Numerous techniques can be applied to increase a site's usability for a visually impaired user. Visually impaired users have to listen to the information on each page and try to remember it. By structuring information into small, manageable groups, faster comprehension and easier recall can be achieved.

4. Provide a Site Map
Site maps can be a useful accessibility tool for visually impaired users as they provide a straightforward list of links to the main pages on the site without any of the fluff in between. Site maps are, of course, useful for everyone, as they provide a means to find pages quickly and help users visualise the structure of a Website.

5. Simple, Easy Language
From an accessibility point of view, this one's important for people with reading and/or cognitive disabilities and for site visitors whose first language isn't the one you write in. From a usability point of view, it helps everyone.

6. Consistent Navigation
Consistent navigation across pages is also an important way to maximise a site's accessibility to those with reading and/or cognitive disabilities, but again, everyone benefits. Each time you visit a new Website, it takes you a few seconds to adjust to the unique layout and user interface of that page. Imagine if you had to do that every time you followed a link to a new page!

7. No Unannounced Pop-Ups
For those of us who use screen readers, pop-ups can be a real accessibility nuisance. Screen readers read out the content of whichever window is located on the "top" -- above all the others.

8. Use CSS for Layout
CSS-based sites generally have a greater ratio of content to HTML code, so they're more accessible to screen readers and search engines alike. Websites that use CSS for layout can also be made accessible to in-car browsers, WebTV and PDAs. Don't underestimate the importance of this! In the year 2008, it's estimated that 58 million PDAs will be sold worldwide.

9. Make Transcripts Available for Audio
One group of Web users with special accessibility needs is the hearing-impaired. These users need written equivalents for audio content. The provision of transcripts is in fact highly beneficial for all users. Many of your site visitors probably can't be bothered to wait for your 3Mb audio file to download and start to play. They may prefer a quick outline of what's contained in the audio content.

10. Screen Flickering and Movement Avoided
Some epileptic Web users must be careful to avoid screen flicker of between 2 and 55 Hz. Web users with reading and/or cognitive disabilities and those using screen magnifiers will struggle to keep up with scrolling text (if you do have scrolling text, be sure to provide a mechanism to stop it