<!DOCTYPE html>
<html>
<head>
<style>
[lang|=en]
{
background:yellow;
}
</style>
</head>
<body>
<p lang="en">Hello!</p>
<p lang="en-us">Hi!</p>
<p lang="en-gb">Ello!</p>
<p lang="us">Hi!</p>
<p lang="zh">nihao!</p>
<p><b>注释：</b>对于 IE8 及更早版本的浏览器中的 [attribute|=value]，必须声明 <!DOCTYPE>。</p>
</body>
</html>