XHTML

What is XHTML?

Extensible Hypertext Markup Language (XHTML) is an upgraded version of HTML. It was developed to work with new technologies such as XML and create a cleaner, more uniform implimentation of HTML.

The Rules

  1. All tags must be lowercase.
  2. All tags must be nested properly.
  3. Web pages must be well formed. This means including the html, head, and body tags in the proper order.
    ( For an example go to: The Basics / Page Outline )
  4. All tags must be closed.
  5. The id attribute should replace the name attribute.
  6. Tables should only be used for tabular data. (This is not a new rule but it is reinforced in XHTML.)
  7. CSS should be used for all decorative design. This includes backgrounds, fonts, and widths.
  8. A web page should have a DOCTYPE at the top of its page.

DOCTYPES

A DOCTYPE (document type declaration) is a way to let a browser know what version of HTML is being used. It has a dramatic affect on the way a web page works and is rendered. There are four types of DOCTYPES: strict, transitional, frameset, and dtd. Not all types work with all versions of HTML or XHTML.