loan bearing the next highest annual percentage rate, until the payment is exhausted. A borrower may instruct or expressly authorize a postsecondary educational lender or servicer to allocate such excess payments in a different manner. (iii) Allocation of exact payments Unless otherwise directed by the borrower upon receipt of a payment that exactly satisfies the monthly payments for each loan, the postsecondary educational lender or servicer shall allocate payments to satisfy each monthly payment. (iv) Promulgation of rules The Director, in accordance with paragraph (17)(A), may promulgate rules for the allocation of payments among multiple postsecondary education loans that— (I) implements the requirements in this section