0019-novalid.html
<!DOCTYPE html>
<html prefix="foaf: http://xmlns.com/foaf/0.1/">
<head>
<meta charset=utf-8>
<title>Test 0019</title>
</head>
<body>
<div about="mailto:manu.sporny@digitalbazaar.com"
rel="foaf:knows" href="mailto:michael.hausenblas@joanneum.at"></div>
</body>
</html>