DOCTYPE

HTML 2.0 DTD



HTML 3.2 DTD



HTML 4.01 Strict, Transitional, Frameset

"http://www.w3.org/TR/html4/strict.dtd">
"http://www.w3.org/TR/html4/loose.dtd">
"http://www.w3.org/TR/html4/frameset.dtd">


XHTML 1.0 Strict, Transitional, Frameset

"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-frameset.dtd">


XHTML 1.1 DTD

"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">

---

Source:
http://www.w3.org/QA/2002/04/Web-Quality