A while back, a major retailer faced a class-action lawsuit because their website was inaccessible to the blind. Prior to this case, most commercial websites weren't affected by the Americans with Disabilities Act (ADA) because they weren't considered “places of public accommodation.” Thanks in part to this high-profile suit, ADA compliance has now become a key consideration for any company using its online presence to enhance its physical stores.

What exactly does that mean? A lot, but I'll try to narrow it down to some common principles defined by the Web Accessibility Initiative (WAI);. This list won’t necessarily make your site ADA compliant, but it will definitely set you off in the right direction — not only in terms of accessibility but general best practices and customer friendliness as well.

1. Alt tags. They enable screen readers to read images and animations, in the case of navigation buttons for example.
2. Encrypted security codes. You know the encrypted code you have to read and then type in, to confirm you are a real human being and not a robot? Screen readers cannot read them. So, if you use them on your site, include an audio file as well that has a descriptive title tag.
3. PDFs. Include an HTML version as well. Screen readers are not yet capable of reading PDFs but will be able to read the HTML version just fine.
4. CSS. It really helps with consistent page organization and structure, including headings and lists.
5. Multimedia. Include captions and descriptions of audio and video.
   

A quick way to perform an automated accessibility validation is to download the free IE Developer Toolbar. While you are viewing the web page in question, simply select Validate > Accessibility > WAI Checklist. It will spit out a handy dandy report that lists rules, whether you failed or passed each applicable rule, and in the case of failure, the element and line of code in question. It’s important to note that there are levels of ADA compliancy, so take that into consideration when reading your report.

Another cool and free ADA compliancy validation app is WAVE. It has a function that enables you to see where the trouble element is from the user’s perspective on the front end rather than solely within the code.  

Note: WAI is not to be confused with Section 508, although they have many overlapping standards. Section 508 is geared toward federal government website accessibility, and WAI generally provides a higher level of accessibility.