be reduced by the amount specified in such election, (ii) the amount determined under paragraph (7) for such calendar year shall be reduced by the amount specified in such election, and (iii) the amount determined under section 42(h)(3)(C)(ii) for such calendar year shall be increased by the sum of the amounts specified in clauses (i) and (ii), except that any amount specified under clause (ii)— (I) may only be allocated under such section to qualified low-income buildings (as defined in section 42) located in a rural area (as defined in paragraph (7), and (II) shall not be taken into account for purposes of determining the unused housing credit ceiling under the second sentence of section 42(h)(3)(C). (B) Time and manner for making election (i) In general An election under this paragraph— (I) shall be made before the end of the calendar year with respect to which such election applies, (II) shall be made in such manner as specified by the Secretary, and (III) shall separately specify the amount of reductions to be made under paragraph (3) and paragraph (7). (ii) Frequency A State housing credit agency may make more than one election under this section with respect to any calendar year, and any such election, once made, shall be revocable only if such revocation is made before the end of the calendar year with respect to which such election is made. (C) Limitation The aggregate amount specified in elections under this paragraph with respect to any State housing credit agency for calendar year shall not exceed the sum of— (i) the amount determined under paragraph (3)(C)(ii) for such calendar year, plus (ii) the amount determined under paragraph (7) for such calendar year. (i) Definitions and special rules For purposes of this section— (1) Middle-income unit (A) In general The term middle-income unit means any unit in a building if— (i) such unit is rent-restricted (as defined in subsection (g)(2)), and (ii) the individuals occupying such unit meet the income limitation applicable under subsection (g)(1) to the