public static function filterRSS($html) {
        $config = array(
            'anti_link_spam' => ['`.`', ''],
            'comment' => 1,
            'cdata' => 3,
            'css_expression' => 1,
            'deny_attribute' => 'on*,style,class',
            'elements' => '*-applet-form-input-textarea-iframe-script-style-object-embed-comment-link-listing-meta-noscript-plaintext-xmp',
            'keep_bad' => 0,
            'schemes' => 'classid:clsid; href: aim, feed, file, ftp, gopher, http, https, irc, mailto, news, nntp, sftp, ssh, telnet; style: nil; *:file, http, https', // clsid allowed in class
            'valid_xhtml' => 1,
            'balance' => 1
        );
        $spec = static::$defaultSpec;

        $result = static::filter($html, $config, $spec);

        return $result;
    }