<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head><title>Hyphenation test</title></head>
<!-- check that xml:lang beats lang -->
<body xml:lang="en-us" lang="x-unknown-language">
<div style="width: 5em; hyphens: auto; font-family:sans-serif;">
supercalifragilisticexpialidocious
</div>
</body>
</html>