Cabinet Office
The development of Web content markup standards continues at a very fast pace. It is for web managers to decide which version of the key markup standards, eg, HTML and CSS, should be employed in the construction of their websites.
At the time of writing this document, the W3C recommendations are XHTML 1.0 and CSS2. Given the current state of browser developments and that of the software tools typically used to generate and maintain websites, it may be appropriate to adopt XHTML 1.0 with CSS1 or HTML 4.01 with CSS1. It may also be appropriate to adopt the 'transitional' rather than 'strict' sub-versions of XHTML 1.0 or HTML 4.01 in order to accommodate browsers that have incomplete or faulty CSS1 implementations.
For information on e-Government Interoperability Framework for information on latest standards visit the following link:
The Open Source (previously W3C) 'Tidy' program can be used to convert HTML to XHTML. Tidy and a number of other available applications can also perform a number of useful jobs, such as, cleaning up the 'bulked out' HTML that is produced by a number of proprietary word processing and HTML editing packages.
Currently, HTML tables are frequently used to effect screen layout designs. Where HTML tables are used for this purpose, care should be taken that the resulting pages work properly with assistive technologies, eg, screen readers that are used to make the Web available to impaired users.
When server-side scripting and related 'dynamic publishing' techniques are employed, consideration should be given to developing an implementation capable of serving markup customised for the browser or other client technology with which a user is accessing the site.
When planning websites that are intended to be long-lived, it should be borne in mind that the appropriate versions of the markup languages and the range of versions of client technology used to access the site will almost inevitably change during the site's lifetime. A strategy for dealing with these evolutionary processes should form a part of the website project plan.
Regardless of which versions of the markup languages are adopted, the critical issues are for web managers to keep abreast of developments and to ensure that their website remains accessible to the full range of client technology with which users visit it. Web managers should ensure that their sites 'transform gracefully' when viewed with older client technology and that their sites do not become 'broken' when viewed in newly released browsers.
See section 4.5 and section 4.6 for specific considerations when using plug-ins, client-side scripting or other client-side active components, also see section 6.3 HTML tables.
The analysis of webserver logfiles can give a useful insight into the range of browsers that visitors use to access the site. Of course, the absence of a browser from the logs may just indicate that the website is inaccessible to that browser.
4.5 Plug-ins
4.6 Scripting and programming
2.4 Building in universal accessibility + checklist
Annex C: HTML editor applications
Annex E: Plug-ins