HTML <optgroup> tag example at PNLdev

Run
<!DOCTYPE html>
<html>
<body>
    <h1>optgroup tag example</h1>
	<form action="/action_page.php">
    <label for="cars">Choose language:</label>
    <select name="language" id="language">
    <optgroup label="html">
    <option value="reference">reference</option>
    <option value="toturial">toturial</option>
    </optgroup>
    <optgroup label="css">
    <option value="reference">reference</option>
    <option value="toturial">toturial</option>
    </optgroup>
    </select>
    <br><br>
    <input type="submit" value="Submit">
	</form>
</body>
</html>