af/pages/errors/404.php

<?php
$bodyclasses = '404 error page';
$title = '404';
$tagline = 'Something\'s wrong';
$description = 'Yep, you are looking for something that is not here.';
?>

<?=i('_header')?>

	<article>
		<header>
			<h2>Nope</h2>
		</header>
		<section>
			<p>Sorry, you are looking for something that is not here.</p>
			<p>And just in case, I'm not a teapot.</p>
		</section>
	</article>
		
<?=i('_footer')?>