<html>
<head>
<style type="text/css">
p.note:before { content: "Note: " }
</style>
</head>
<body>
    <h1>Html Heading</h1>
    <p>fzz</p>
    <h2>Html Heading</h2>
    <p class="note">fzz</p>
    <p>fzz</p>
    <p class="note">fzz</p>
</body>
</html>