D.C. Code § 9-915: Credit of the District not pledged.

Revenue bonds issued under the provisions of this chapter shall not constitute a debt of the District nor a pledge of the faith and credit of the District. The bonds shall be payable solely from funds provided for the bonds from revenues. The issuance of revenue bonds under the provisions of this chapter shall not directly, indirectly, or contingently obligate the District to any form of taxation whatever. All revenue bonds shall contain a statement on their face substantially to this effect.