<!DOCTYPE html>
<html>

<head>
    <meta charset="utf-8">
    <title>Required label examples</title>
</head>

<body>
    <form>
        <p><abbr title="必填">*</abbr>为必填项目。</p>

        <!-- 因此 -->
        <!--<div>
          <label for="username">名字：</label>
          <input type="text" name="username">
          <label for="username"><abbr title="必填">*</abbr></label>
        </div>-->

        <!-- 这样写更好 -->
        <!--<div>
          <label for="username">
         