12 C.F.R. § 1282.38
(f) Affordability of manufactured housing communities. For an Enterprise purchase of a blanket loan on a manufactured housing community, unless otherwise determined by FHFA, the affordability of the homes in the community shall be determined using one of the methodologies in paragraphs (f)(1) or (f)(2) of this section, as applicable, except that for purposes of determining extra credit for residential economic diversity activities or objectives, the methodology in paragraph (f)(2) of this section may not be used.
(2) Census tract methodology for any type of manufactured housing community. For any type of manufactured housing community, except for purposes of determining extra credit for residential economic diversity activities or objectives, the affordability of the homes in the community is determined as follows:
(g) Application of median income.—(1) To determine an area's median income under §§ 1282.17 through 1282.19 and the definitions in § 1282.1, the area is:
(2) When an Enterprise cannot precisely determine whether a mortgage is on dwelling unit(s) located in one area, the Enterprise must determine the median income for the split area in the manner prescribed by the Federal Financial Institutions Examination Council for reporting under the Home Mortgage Disclosure Act (12 U.S.C. 2801 et seq.), if the Enterprise can determine that the mortgage is on dwelling unit(s) located in: