Media types summary for serving XHTML documents

Media type
HTML 4
XHTML 1.0
(HTML compatible)
XHTML 1.0
(other)
XHTML
Basic / 1.1
XHTML+MathML

text/html
SHOULD
MAY
SHOULD NOT
SHOULD NOT
SHOULD NOT

application/xhtml+xml
MUST NOT
SHOULD
SHOULD
SHOULD
SHOULD

application/xml
MUST NOT
MAY
MAY
MAY
MAY

text/xml
MUST NOT
MAY
MAY
MAY
MAY

The above 'table' has been based on material originally found at XHTML Media Types[2]

Notes:

References:

  1. http://www.xml.com/lpt/a/2003/03/19/dive-into-xml.html
  2. http://www.w3.org/TR/xhtml-media-types/#summary
  3. http://www.w3.org/TR/xhtml1/#guidelines
  4. http://www.w3.org/MarkUp/2004/xhtml-faq#texthtml
  5. http://www.w3.org/International/articles/serving-xhtml/
  6. http://www.hixie.ch/advocacy/xhtml
  7. http://devedge.netscape.com/viewsource/2003/xhtml-style-script/
  8. http://www.rfc-editor.org/rfc/rfc2119.txt

Conclusion:

If you want your webpages to work in Internet Explorer stick with HTML 4.01 served as text/html.