XHTML (eXtensive Hyper Markup Language) is considered to be a more structured language and a more flexible language than XHTML. It is recommended that XHTML be used together with Cascading Style Sheets to develop web pages. Using this emerging technology to develop web pages can make the generation of alternative displays for content much easier e.g. the blingaisa website shows how a text-only version of a page can be created without any loss of content using Cascading Style Sheets. XHTML also allows a web developer to write code that is well structured e.g. It not allow an opening tag without a corresponding closing tag. If code is well structured then it is likely to result is a more accessible web page.
A well-designed XHTML page is likely to limit the amount of code on the page. This means the page can be more easily read by assistive technology such as screen readers. If a page does not contain any unnecessary code it is likely to be listed higher in the search engines, because the search engine spiders are able to index the information more easily.
XHTML is a completely different language to HTML with its own syntax, this means that the accessibility tags such as tab index and access key may well have different names in XHTML. This website focuses on accessible website design in HTML, therefore this page is designed to give the reader a brief introduction to HTML. For the interested reader there are links to further information.
Web developers wishing to develop a web page using XHTML need to declare an XHTML DOCTYPE at the top of the web page. A source code example of this is given below.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
Besides 1.0 Strict there are also other forms of XHTML that a web developer can use to develop their pages these include 1.0 Transitions, 1.0 Frameset, XHTML 1.1 etc. If a web developer wishes to use one of these forms of XHTML then all they have to do is replace the 1.0 Strict in the above example, with the type of XHTML that they wish to use. More information about the different XHTML DOCTYPES can be found on the World Wide Consortium website. The web address at the end of the declaration in the example above is required so that the browser knows the address of the web page.
XHTML is a completely different language with completely different syntax to HTML, which means that accessibility tags such as accesskey and tabindex may have different names in XHTML. Therefore this page, has been designed to give a brief introduction to XHTML. For the interested reader there are links to further information.
The World Wide Web Consortium has produced a full set of guidelines for developing pages in XHTML. These are very similar to the WCAG 1.0 guidelines that are described on the WCAG 1.0 page the World Wide Web Consortium website contain full details about the XHTML guidelines. The web develop should note that these are general guidelines and are unlike the WCAG 1.0 standard they are not directly related to Web Accessibility e.g. all tags need to be written in lower case. The World Wide Web Consortium is also currently working on the second version of the XHTML standard. The World Wide Consortium has also produced guidelines for the modularisation of XHTML.
If a web developed has developed a web page in XHTML, then there are number of validators available on the Internet that can be used to validate the XHTML code on a web page. One such validator can be found on the World Wide Web Consortium’s website.