private function findIdNotFormated($id, &$yAlreadySet, &$realNameId) {
        $tofind = $id;

        while (strlen($tofind) >= 2) {
            if ($this->idExists($tofind, $yAlreadySet, $realNameId)) {
                return $tofind;
            } else {
                $tofind = substr($tofind, 0, -1);
            }
        }

        if ($this->allowsUnknownIdentifier === false) {
            throw new CINParseException('gs1128', 'Error in formatting, can\'t find an identifier.');
        }

        return false;
    }