外部檔案連線：<link rel ="stylesheet" type=""text/css" href="demo.css"/>
內聯CSS：<style type="text/css">
a:link img{
filter:gray;
}
a:hover img{
filter:"";
}
</style>
html規範：<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
編碼格式：<meta http-equiv="content-type" content="text/html;charset=utf-8"/>
PHP檔案亂碼：header("Content-type:text/html;charset=utf-8");
json格式化：header("Content-type:text/json;charset=utf-8");