<small>

부트 스트랩에서 HTML <small>요소는 모든 제목에 더 가벼운 보조 텍스트를 만드는 데 사용됩니다.

예
h1 heading secondary text
h2 heading secondary text
h3 heading secondary text
h4 heading secondary text

h5 heading secondary text

h6 heading secondary text

[전체소스]
<!DOCTYPE html>
<html lang="en">
<head>
<title>Bootstrap Example</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
</head>
<body>

<div class="container">
<h1>Lighter, Secondary Text</h1>
<p>The small element is used to create a lighter, secondary text in any heading:</p>
<h1>h1 heading <small>secondary text</small></h1>
<h2>h2 heading <small>secondary text</small></h2>
<h3>h3 heading <small>secondary text</small></h3>
<h4>h4 heading <small>secondary text</small></h4>
<h5>h5 heading <small>secondary text</small></h5>
<h6>h6 heading <small>secondary text</small></h6>
</div>

</body>
</html>