Pub. L. 92-181, tit. IV, pt. C, sec. 4.16
Prohibition Against Tax-Exempt Guarantees.—
Sec. 4.16. Prohibition Against Tax-Exempt Guarantees.—Notwithstanding any other provision of this Act, no guarantee shall be made on any instrument of indebtedness the income from which is exempt in whole or in part from Federal taxation.