fieldset

The child is a legend element. The child is not out-of-flow (e.g. not absolutely positioned or floated). The child is generating a box (e.g. it is not 'display:none').

<form action="" method="post">
 <fieldset>
 <legend>Title</legend>
 <label for="radio">Click me</label>
 <input type="radio" name="radio" id="radio">
 </fieldset>
</form>
Title
Read more on w3.org