Form Mastery - HTML5 Mastery: Semantics, Standards, and Styling - page 170

Figure 4-28. An example of the usual rendering of a fieldset
To identify each fieldset , you must use the legend element:
<fieldset>
<legend>Cheeses of the world</legend>
<p>
<select name="cheesemenu">
<option>Cheddar</option>
<option>Stilton</option>
<option>Brie</option>
</select>
</p><p>
<button type="submit">Submit!</button>
</p>
</fieldset>
The form will now look something like Figure 4-29 .