group means an affiliated group as defined in section 1504(a), determined— (i) by substituting more than 50 percent for at least 80 percent each place it appears, and (ii) without regard to paragraphs (2) and (4) of section 1504(b). (C) Allocation of deduction Except as provided in regulations, the deduction under subsection (a) shall be allocated among the members of the expanded affiliated group in proportion to each member's respective amount (if any) of qualified textile production activities income. (2) Trade or business requirement This section shall be applied by only taking into account items which are attributable to the actual conduct of a trade or business. (3) Unrelated business taxable income For purposes of determining the tax imposed by section 511, subsection (a)(1)(B) shall be applied by substituting unrelated business taxable income for taxable income . (4) Regulations The Secretary shall prescribe such regulations as are necessary to carry out the purposes of this section, including regulations which prevent more than 1 taxpayer from being allowed a deduction under this section with respect to any activity described in subsection (c)(4)(A). . (2) Conforming amendments (A) (i) Section 74(d)(2)(B) of the Internal Revenue Code of 1986 is amended by inserting 251, after 221, . (ii) Section 246(b)(1) of such Code is amended by inserting 251, after 243(a)(1), . (iii) Section 469(i)(3)(E)(iii) of such Code is amended by inserting 251, after 250, . (B) Section 170(b)(2)(D) of such Code is amended by striking the period at the end of clause (v) and inserting , and and by adding at the end the following new clause: (vi) section 251. . (C) Section 172(d) of such Code, as amended by this Act, is amended by adding at the end the following new paragraph: (11) The deduction under section 251 shall not be allowed. . (3) Clerical amendment The table of sections for part VIII of subchapter B of chapter 1 of such Code is amended by adding at the end the following new item: Sec. 251. Income attributable to