Apologize for my bad php knowledge, how to set html5 flag for the current document? Something like:
$document->setHtml5(true);
This to be executed in template.php where we do not have $document.
My template lacks support for this flag, but in head.php we have:
if ($document->isHtml5())
{
$buffer .= $tab . '<meta charset="' . $document->getCharset() . '" />' . $lnEnd;
}