(a) Regulations. All Retirement Plan Bonds shall be subject to the general regulations prescribed by the Secretary with respect to United States securities, which are set forth in Treasury Department Circular No. 300, current revision, to the extent applicable. Copies of the general regulations may be obtained upon request from any Federal Reserve Bank or Branch or the Bureau of the Fiscal Service.

(b) Reservation as to issue of bonds. The Secretary of the Treasury reserves the right to reject any application for the purchase of Retirement Plan Bonds, in whole or in part, and to refuse to issue or permit to be issued any such bonds in any case or any class or classes of cases if he deems such action to be in the public interest, and his action in any such respect shall be final.

(c) Additional requirements. In any case or any class of cases arising under this part the Secretary of the Treasury may require such additional evidence as may in his judgment be necessary, and may require a bond of indemnity, with or without surety, where he may consider such bond necessary for the protection of the United States.

(d) Waiver of requirements. The Secretary of the Treasury reserves the right, in his discretion, to waive or modify any provision or provisions of this circular in any particular case or class of cases for the convenience of the United States, or in order to relieve any person or persons of unnecessary hardship, if such action is not inconsistent with law, does not impair any existing rights, and he is satisfied that such action would not subject the United States to any substantial expense or liability.

(e) Fiscal agents. Federal Reserve Banks and Branches, as fiscal agents of the United States, are authorized to perform such services as may be requested of them by the Secretary of the Treasury in connection with the issue, delivery, redemption, reissue, and payment of Retirement Plan Bonds.

(f) Reservation as to terms of circular. The Secretary of the Treasury may at any time, or from time to time, supplement or amend the terms of this part, or any amendments or supplements thereto.