private function _exportComment($text = '')
{
// see https://www.mediawiki.org/wiki/Help:Formatting
$comment = $this->_exportCRLF();
$comment .= '<!--' . $this->_exportCRLF();
$comment .= htmlspecialchars($text) . $this->_exportCRLF();
$comment .= '-->' . str_repeat($this->_exportCRLF(), 2);
return $comment;
}