Standards compliance

All pages on this site aim to comply guidelines of the W3C Web Content Accessibility Guidelines version 2.0 and to satisfy the level AA requirements. More information about the guidelines is available on the W3C’s Web Accessibility Initiative page.

The following technologies are used on

  • XHTML5 + RDFa
  • CSS
  • JavaScript

All pages validate as XHTML5+RDFa polyglot and use structured semantic markup.

Tables aim to have properly named header cells, to allow screen readers to render them intelligently. Where applicable tables also have a caption and a summary.

Where content cannot be provided in an accessible format on the main website, a suitable accessible alternative will be offered.

The website has also been tested for the following:

  • For colour contrast by adhering to WCAG 2.0 AA levels of colour contrast
  • A range of screen resolutions
  • On different platforms – MAC and PC
  • A range of different browsers
  • Without images - a text equivalent is displayed for non-decorative images
  • Without Cascading Style Sheets – it still works, the content is available and makes sense

In addition to this there are services available which make use of the following technologies:

  • PDF
  • Atom Feeds
  • JSON

Text size

If you find the text on this site too small or too big, you can change it using your browser settings. The default size for most browsers is "100%". Below are links to instructions for changing the text size for some common browsers.

We would like to hear from you if you have had trouble with the text size on this website. Please tell us your operating system, for example "Windows XP"; your browser, for example "Internet Explorer 5.5" and your Internet Service Provider, for example "AOL" or "BT". We would also like to know what size you have chosen as your browser text size, for example "medium".

Skip links

We use skip links that allow users to access the main content, skipping common structures such as titles and navigation.


All links can be followed in any browser, even if scripting is turned off.

For links opening a new window or for file downloads which may carry the file format or a textual description of an icon, title attributes describe the links in greater detail. There are no javascript: pseudo-links.

External links

All external links will load in a new window. This applies to all PDFs and external sites.

PDF Documents

A number of documents available for viewing from this site are in Adobe® Acrobat® Portable Document Format (PDF). PDF format is used to preserve the content and layout of our publications.

People using screen-reading devices may be unable to read PDF documents directly until they have an accessibility plug-in installed on their system. This plug-in is often available for free (for example from Adobe) and your screen reader may do this automatically. Adobe also has online tools that will convert PDF files to HTML on request. To get the plug-in and latest news about Adobe’s accessibility tools and services, visit the Adobe Accessibility Resource Centre.


This site uses javascript for some pieces of functionality, such as displaying help tips alongside an ‘?’ icon and for improve user experience. If Javascript is disabled in your browser, we have provided a ‘no-Javascript’ version of the page that still enables access to this content.

Javascript is not required to view and access any of the notice content on this site

Conformance claim dated: 11 January 2014