Recommendation
Date: Jan. 26, 2000
Link: http://www.w3.org/TR/xhtml1/
Source Author or Organization: W3C
Excerpted from "Abstract": "This specification defines XHTML 1.0, a reformulation of HTML 4 as an XML 1.0 application, and
three DTDs corresponding to the ones defined by HTML 4. The semantics of the elements and
their attributes are defined in the W3C Recommendation for HTML 4. These semantics provide
the foundation for future extensibility of XHTML. Compatibility with existing HTML user agents is
possible by following a small set of guidelines."