slide 29

XHTML provides

• XML DTDs for HTML 4.0

  (Did you know that HTML 4.0 was defined with three SGML DTDs? Most people and applications used the tags from HTML 4.0 but ignored the DTDs. Most current HTML isn't SGML, but it could have been)

• The ability to create HTML that is also Valid XML (using a public DTD)
• The advantages of Case 2, plus expectation that others will know how to process your HTML.

XHTML specification available at: http://www.w3.org/TR/xhtml1