24 C.F.R. § 905.304
(a) Period of obligation to operate as public housing. The PHA shall operate all public housing projects in accordance with the CF ACC, as amended, and applicable HUD regulations, for the statutorily prescribed period. These periods shall be evidenced by a recorded DOT on all public housing property. If the PHA uses Capital Funds to develop public housing or to modernize existing public housing, the CF ACC term and the covenant to operate those projects are as follows:
(b) Mortgage or security interests. The PHA shall not allow any mortgage or security interest in public housing assets, including under section 30 of the 1937 Act (42 U.S.C. 1437z-2), without prior written approval from HUD. PHAs that undertake financing unsecured by public housing assets shall include the following nonrecourse language in all financing documents as follows:
“This financing is non-recourse to any public housing property (real or personal property including all public housing assets or income), or disposition proceeds approved pursuant to Section 18 of the United States Housing Act of 1937 (unless explicitly permitted by HUD in the Section 18 approval letter).”