Where an order is made in relation to the member spouse's retirement benefit (hereinafter referred to as the "subsequent order") and an order has previously been made in relation to the member spouse's retirement benefit from the same pension scheme (hereinafter referred to as the "previous order") the designated benefit payable from the pension scheme pursuant to the subsequent order shall be calculated in accordance with the relevant regulations of this Part but so that where the member spouse's retirement benefit is calculated on a defined benefit basis any reduction in retirement benefit in respect of designated benefit payable pursuant to the previous order shall be ignored.