<html>
<head>
<style>
[lang|=en]
{
color:blue;
}
</style>
</head>
<body>
<h2>Will apply to:</h2>
<p lang="en">Hello!</p>
<p lang="en-us">Hi!</p>
<p lang="en-gb">Ello!</p>
<hr>
<h2>Will not apply to:</h2>
<p lang="us">Hi!</p>
<p lang="no">Hei!</p>
</body>
</html>