HTML 4.0 ???

Wie retro!
Code:
Here is an example of an XHTML 1.1 document.
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" >
<head>
<title>Virtual Library</title>
</head>
<body>
Moved to vlib.org.</p>
</body>
</html>
http://www.w3.org/TR/2001/REC-xhtml1...nformance.html