XHTML Checklist

This is a list of the most common requirements for XHTML as per the W3C. Also see HTML for the World Wide Web, Chapter 1, page 36.

Start the document like this:

  • <!DOCTYPE html PUBLIC “-//W3C//DTD XHTML 1.0 Transitional//EN”
    “http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd”>
  • Define your File Type with: <html xmlns=”http://www.w3.org/1999/xhtml”>

In the head section, add the character set (optional):

  • <meta http-equiv=”Content-Type” content=”text/html; charset=iso-8859-1″ />

Use this formatting as needed:

  • 4.1. Documents must be well-formed
    • All elements must have closing tags: <p>paragraph</p>
      and <img scr=”pic.jpg”
      />
    • All the elements must nest properly: <p><b>Nested
      tags</b></p>
  • 4.2. Element and attribute names must be in lower case.
    • for all HTML element and attribute names: <a
      href
      =”#” target=”_blank“>
  • 4.3. For non-empty elements, end tags are required
    • <hr width=75% noshade=”noshade” />
  • 4.4. Attribute values must always be quoted:
    • <p class=menu>
  • 4.5. Attribute Minimization
    • Attribute-value pairs must be written in full:
      • <dl compact=”compact”>
  • 4.6. Empty Elements
    • Empty elements must either have an end tag or the start tag must
      end with />:
      <br /><hr />
  • C.13. Cascading Style Sheets (CSS) and XHTML
    • Use lower case element and attribute names.
    • In tables, add a tbody element to a table if it is referred to
      in a CSS selector.