<html>
<body>
<label>Choose your meal:<label>
<select>
<optgroup label="Meat">
<option value="chicken">Chicken</option>
<option value="beef">Beef</option>
</optgroup>
<optgroup label="Veggie">
<option value="eggplant">Eggplant</option>
<option value="pasta">Pasta</option>
</optgroup>
</select>
</body>
</html>
The optgroup element creates a group of options that can be included inside of a select list.
A live example:
N of