The following code shows how to mark star icon.
<!DOCTYPE html>
<html>
<head>
<link rel="stylesheet" type="text/css"
href="http://netdna.bootstrapcdn.com/twitter-bootstrap/2.2.2/css/bootstrap-combined.min.css">
<script type='text/javascript'
src="http://netdna.bootstrapcdn.com/twitter-bootstrap/2.2.2/js/bootstrap.min.js"></script>
</head><!--from w w w . j a va 2 s. c o m-->
<body>
<div class="form-horizontal">
<div class="control-group row-fluid form-inline">
<label for="name" class="control-label">
<p class="text-info">
Name <i class="icon-star"></i>
</p>
</label>
<div class="controls">
<input type="text" id="name" placeholder="Enter your name"
class="span3">
</div>
</div>
</div>
</body>
</html>