(a) The purpose of this part is to provide a basis for determining tax exemption of obligations issued by public housing agencies pursuant to Section 11(b) of the United States Housing Act of 1937 (42 U.S.C. 1437i) to refund bonds for Section 8 new construction or substantial rehabilitation projects.

(b) This part does not apply to tax exemption pursuant to Section 11(b) for low-income housing projects developed pursuant to 24 CFR parts 950 and 941.