Web Content Accessibility Guidelines (WCAG)

The guidelines which are centrally accepted for the accessible design of websites are the "Web Content Accessibility Guidelines 1.0" (WCAG 1.0). The World Wide Web Consortium (W3C) published these guidelines on 5th May 1999. The guidelines include requirements for programming as well as content structure, layout and the usage of certain technology. The WCAG 1.0 has meaning worldwide and applies as the basic reference upon which other guidelines are built. Many countries use the WCAG (1.0) to orientate themselves. The German Barrier-free Information Technology Regulation (Barrierefreie Informationstechnik Verordnung - BITV) was developed according to the World Wide Web Consortium (W3C) guidelines.

Overview: World Wide Web Consortium (W3C)

In 1994, a commission was founded whose aim was to standardise internet technology (World Wide Web Consortium - W3C ). The W3C is not a well known inter-country organisation and therefore not able to specify firm standards. Nevertheless, their recommendations are relevant worldwide and they are generally acknowledged.

One of the most important concerns of W3C is to make the internet accessible to as many people as possible. The Web Accessibility Initiative (WAI) was arranged for this purpose. The WAI promotes freedom from barriers on the internet.

Set up of the WCAG 1.0

The WCAG 1.0 includes 14 guidelines with a total of 66 checkpoints. The guidelines are divided into to subject areas. Guidelines 1 to 11 ensure that websites remain easy to use for different types of disabilities. The remaining guidelines deal with the understandability, layout and content of the website.

The checkpoints are arranged in 3 priority levels in descending order. A checkpoint must fulfil priority 1 otherwise not all user groups can access information. Priority 2 is fulfilled by making access easier for a few user groups. Priority 3 is for websites which are considered to be particularly user friendly and minimise all barriers. 

The websites are assigned one of 3 conformance levels (A, AA or AAA), depending on which checkpoints are fulfilled:

  • A: All checkpoints of priority 1 are fulfilled.
  • AA: All checkpoints of priority 1 and 2
  • AAA: All checkpoints of priority 1, 2 and 3 are fulfilled.

Further Development WCAG 2.0

The WCAG is constantly being developed. The layout has been Version 2.0 for sometime. As the basic objectives did not differ from the first version, the layout was completely revised. WCAG 2.0 contains 13 guidelines which are divided into 4 principles with a total of 70 success criteria. 

The 4 principles are:

  • Perceptibility: The contents must be perceivable. For example, the contrast between text and background must be adequate.
  • Usability: All functions must be usable. For example, the navigation must also function without the use of a mouse.
  • Understandability: The content and control elements must be understandable. Simple language must be ensured.
  • Technically Robust: The contents must be designed so that they can also function with both today's technology and that of the future. For example, websites must be able to be displayed in newer browsers.

The guidelines, principles and success criteria state what is required in order to achieve conformity. In addition, WCAG 2.0 also contains information which is helpful for the understanding and implementation of the success criteria. WCAG 2.0 is free from technical referencing and is not limited to HTML and CSS. Therefore they are easily able to be used on other web technologies as well.

The information should be made available to a wide audience. It should therefore be ensured that during development, the guidelines are understandable and easily able to be translated into another language, so that they can be devolved into national law.

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