Wrap up handbook title with UTF-8 version of htmlspecialchars().
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="<?php echo DEFAULT_LANGUAGE_CODE; ?>" lang="<?php echo DEFAULT_LANGUAGE_CODE; ?>">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
- <title><?php echo _AT('Transformable_handbook'); ?></title>
+ <title><?php echo htmlspecialchars(_AT('Transformable_handbook'), ENT_QUOTES, 'UTF-8'); ?></title>
<script type="text/javascript">