§ 508. Administration by the attorney general. The attorney general may make rules and regulations necessary for the administration of this article; provided, however, that such rules and regulations shall not attempt to regulate or characterize rental-purchase agreements as a security interest, credit sale, retail installment sale, conditional sale or any other form of consumer credit that imputes to a rental-purchase agreement the creation of a debt or extension of credit, nor shall such rules and regulations require the disclosure of a percentage rate calculation, including a time-price differential, an annual percentage rate, or an effective annual percentage rate.