Accessibility guidelines

Accessibility standards explained

Web Content Accessibility Guidelines 1.0 and 2.0

The World Wide Web Consortium’s Web Accessibility Initiative (WAI) has carried out extensive work on web accessibility and their comprehensive set of guidelines, the Web Content Accessibility Guidelines (WCAG 1.0), published in May 2000, became the accepted international standard for ensuring accessibility of websites for people with various disabilities, regardless of the technology they use to access the web. Most institutions worldwide that are legally required to make their websites accessible base their own guidelines on this standard.

In December 2008, WAI published a new updated version of their guidelines, WCAG 2.0, which have been ‘developed to apply to more advanced Web technologies, be easier to use and understand, and be more precisely testable’.

Implementing Web Content Accessibility Guidelines 2.0

We are currently reviewing WCAG 2.0 and working towards a plan for implementing the new guidelines on our site. The fundamental issues of web accessibility remain the same in the 2 versions. For now WCAG 1.0 is the standard we continue to work to; once we have a full implementation plan established for WCAG 2.0, we will start applying it to our pages.

Web Content Accessibility Guidelines 1.0

The full WCAG 1.0 guidelines are very detailed and extensive. They are, however, broken down into individual checkpoints which are prioritised according to their impact on accessibility (see WAI's summarised list of checkpoints):

Priority 1 checkpoints are those which must be satisfied, otherwise one or more groups of web users will find it impossible to access information on our pages. Satisfying these checkpoints is a basic requirement to removing the most obvious barriers to accessibility.

Priority 2 checkpoints are points which should be satisfied, or one or more groups of users will find it difficult to access information on our pages. Satisfying these removes significant barriers to accessibility.

Priority 3 checkpoints are points which may be satisfied, or one or more groups of users will find it somewhat difficult to access information on our pages. Satisfying these improves accessibility.

In common with most organisations, the Web Team recommends that we aim for our pages to comply as far as possible with the Priority 1 and 2 checkpoints. This is the standard we have adopted, described as ‘WCAG 1.0 AA standard’ in our Accessibility Statement.

In practice, there has to be some flexibility in how far we can go towards compliance, as the guidelines are open to interpretation, and if adhered to literally can occasionally cause problems as much as solve them. Most of the guidelines highlight potential barriers in the way web pages can be designed that compromise the flexibility that allows users to set their own preferences in the way they access web pages. Wherever there is a query over how or whether to comply with a specific guideline, the rule of thumb is, ‘if we don't do something about this, will we be making it either impossible or difficult for one or more groups of users to access the information on our pages?’ If the answer is Yes, then you need to find a solution - if you are not sure what to do about a certain issue with your page, contact the Web Team for assistance. However, it is increasingly recognised that making web pages universally accessible to all is practically impossible. As a last resort, and especially where there may be a conflict between the needs of different groups of users, the solution may be to present the information in a different way for those groups who may be affected, as long as the way it is presented to them does not disadvantage them in any way, and they are provided with the same level of service. However, if possible, it is always preferable to have the information or service available in a single format for all users.

For detailed guidance, you can view our quick checklist of the main issues for web content authors from WCAG 1.0 Priority 1 and 2 guidelines. These issues are also all incorporated into the practical guidance on specific elements of web content for Site Manager users.

Valid XHTML and CSS

XHTML and CSS are ‘languages’ used by computer software, such as browsers, to determine how to display a web page. These ‘languages’ have vocabulary and grammatical rules, and using these rules according to the published grammars assists in making your web pages comprehensible to as wide a range of browsing and assistive software as possible. Whilst valid code does not guarantee accessibility, it can go a long way towards avoiding some of the worst accessibility pitfalls.

If possible, and if you have the necessary knowledge of html, you should really validate your code. For more information about why, see the W3C’s Validation Service ‘Why Validate?’ page. For ways to check your code is valid, please see our recommended checking methods.