Reference: Conforming XHTML 1.0 Frameset Template
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Frameset//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-frameset.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Conforming XHTML 1.0 Frameset Template with accessibility</title>
</head>
<frameset>
<noframes>
<body>
<!-- place alternative information for accessibility purposes here -->
</body>
</noframes>
</frameset>
</html>