protected function italic_tag_rule($match) {
        $text = $match[1];
        if(strlen($match[2]) == 5) {
            $text .= "''";
        }
        
        $this->rules($text, array('only' => array('bold')));
        if(strpos($text, "''") !== false) {
            $text = str_replace("''", $this->protect("''"), $text);
        }
        
        return array($text, array());
    }