Target WCAG 2.0 Level

At minimum, new sites or web sites that have undergone substantial change will also comply with WCAG 2.0 Level AA. Whenever possible, we should comply with the even stricter standard of WCAG 2.0 Level AAA.

The four principles

The overall goal for accessibility is to create web content that is perceivable, operable and understandable by the broadest possible range of users and compatible with their wide range of assistive technologies, now and in the future. These principles have numerous "techniques" that describe how to implement web accessibility.  The basic principles include:

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Understandable

Information and the operation of the user interface must be understandable. That means the user must be able to understand the information as well as the operation of the user interace. The content cannot be beyond their understanding.

Common Understandable issues

Robust

Web content must be robust enough that it can be interpreted reliably by a wide variety of user agents, including assistive technologies (AT). This means that users must be able to access web content as technologies advance. Software updates to user agents and AT should not matter when it comes to web content and accessibility.

WCAG

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Common Robust issues

General Guidelines (for level A and AA)

Guideline 1.1

Text Alternatives: Provide text alternatives for any non-text content (more info|http://www.w3.org/TR/WCAG20/#text-equiv-all)

• All images, form image buttons, and image map hot spots have appropriate, equivalent alternative text.
• Images that do not convey content, are decorative, or contain content that is already conveyed in text are given null alt text (alt="") or implemented as CSS backgrounds. All linked images have descriptive alternative text.
• Equivalent alternatives to complex images are provided in context or on a separate (linked and/or referenced via longdesc) page.
• Form buttons have a descriptive value.
• Form inputs have associated text labels.
• Embedded multimedia is identified via accessible text.
• Frames are appropriately titled.

Guideline 1.3

Adaptable: Create content that can be presented in different ways (for example simpler layout) without losing information or structure

• Semantic markup is used to designate headings (<h1>), lists (<ul>, <ol>, and <dl>), emphasized or special text (<strong>, <code>, <abbr>, <blockquote>, for example), etc. Semantic markup is used appropriately.
• Tables are used for tabular data. Where necessary, data cells are associated with their headers. Data table captions and summaries are used where appropriate.
• Text labels are associated with form input elements. Related form elements are grouped with fieldset/legend.

Guideline 1.4

Distinguishable: Make it easier for users to see and hear content including separating foreground from background

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• If the same visual presentation can be made using text alone, an image is not used to present that text.

Guideline 2.1

Keyboard Accessible: Make all functionality available from a keyboard

• All page functionality is available using the keyboard, unless the functionality cannot be accomplished in any known way using a keyboard (e.g., free hand drawing).
• Page-specified shortcut keys and accesskeys (accesskey should typically be avoided) do not conflict with existing browser and screen reader shortcuts.

Guideline 2.4

Navigable: Provide ways to help users navigate, find content, and determine where they are

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• It is visually apparent which page element has the current keyboard focus (i.e., as you tab through the page, you can see where you are).

Guideline 3.2

Predictable: Make Web pages appear and operate in predictable ways

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• Elements that have the same functionality across multiple web pages are consistently identified. For example, a search box at the top of the site should always be labeled the same way.

Guideline 3.3

Input Assistance: Help users avoid and correct mistakes

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• If an input error is detected (via client-side or server-side validation), provide suggestions for fixing the input in a timely and accessible manner.

Guideline 4.1

Compatible: Maximize compatibility with current and future user agents, including assistive technologies

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• Markup is used in a way that facilitates accessibility. This includes following the HTML/XHTML specifications and using forms, form labels, frame titles, etc. appropriately.

Tools

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Accessibility tools and scanners

Manually sifting through code to determine accessibility issues is a long drawn out process. Thankfully, there are tools to help you on this endeavor!