WCAG (Wu-CAHG) stands for the “Web Content Authoring Guidelines”, put forth by the W3C (World Wide Web Consortium). WCAG 1.0 was released as a Recommendation in 1999, and WCAG 2.0 is now in Candidate Recommendation status.
WCAG lists three levels of compliance. The definition of the levels seems somewhat backwards: by not complying to a certain level, you are barring access to certain groups of individuals:
- Priority 1: one or more groups will find it impossible to access information in the document.
- Priority 2: one or more groups will find it difficult to access information in the document.
- Priority 3: one or more groups may find it difficult to access information in the document.
One of the most important things to know about WCAG is that there is no governing body to enforce compliance. These are guidelines, not laws. That being said, many organizations model their accessibility policy after these guidelines, or will publicly state their commitment to following these guidelines. Even with no external governance, an organization that does not fulfill an stated commitment stands to suffer from negative perception by users.
When WCAG 2.0 was first drafted, it met with much industry critique as being too difficult to understand and too technology-agnostic. It has gone through extensive revision and it now close to being considered a formal recommendation.
The new guidelines offer more quantifiable success measures: whereas the techniques for satisfying WCAG 1.0 stated that there should be “sufficient contrast” between foreground and background colors, WCAG 2.0 techniques explicitly call out color contrast ratios to satisfy.
As in any case, meeting guidelines or standards does not guarantee that a site visitor will have a positive experience or be able to complete his tasks. However, these guidelines can help a site designer or developer identify common areas of difficulty and work to eliminate those.