举例熟悉网页的头部信息表示涵义
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd"><>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312"><>
<meta http-equiv="expires" content="2008/10/15 18:00:00"><>
<meta http-equiv="pragma" content="no-cache"><>
<meta http-equiv="Refresh" content="5;http://www.jb51.net"><>
<meta http-equiv="set-cookie" content="2007/10/18 18:00:00"><>
<meta http-equiv="Window-target" content="_top"><>
<meta http-equiv="Page-Enter" content="revealTrans(duration=1000000,transition=50000000)"><>
<meta http-equiv="Page-Exit" content="revealTrans(duration=1000000,transition=50000000)"><>
<meta name="keywords" content="web,jb51,webdesign"><>
<meta name="description" content="哈哈哈哈哈"><>
<title>标题一定不要少啊！对SEO很有用的！</title>
</head>
<body>
aaa
</body>
</html>