; except that, in applying such provisions for such purposes— (A) the term gross rent shall have the meaning given such term by paragraph (2)(B) of this subsection, and (B) the term applicable income limit means the limitation under paragraph (1) of this subsection. (5) Election to treat building after credit period as not part of a project For purposes of this section, the taxpayer may elect to treat any building as not part of a qualified middle-income housing project for any period beginning after the credit period for such building. (6) Special rule where de minimis equity contribution Property shall not be treated as failing to be residential rental property for purposes of this section merely because the occupant of a residential unit in the project pays (on a voluntary basis) to the lessor a de minimis amount to be held toward the purchase by such occupant of a residential unit in such project if— (A) all amounts so paid are refunded to the occupant on the cessation of his occupancy of a unit in the project, and (B) the purchase of the unit is not permitted until after the close of the credit period with respect to the building in which the unit is located. Any amount paid to the lessor as described in the preceding sentence shall be included in gross rent under paragraph (2) for purposes of determining whether the unit is rent-restricted. (7) Scattered site projects Buildings which would (but for their lack of proximity) be treated as a project for purposes of this section shall be so treated if all of the dwelling units in each of the buildings are rent-restricted (within the meaning of paragraph (2)) residential rental units. (8) Waiver of certain recertifications On application by the taxpayer, the Secretary may waive any annual recertification of tenant income for purposes of this subsection, if the entire building is occupied by middle-income tenants. (9) Clarification of general public use requirement A project does not fail to meet the general public use requirement solely because of occupancy