controlled group of corporations
(3) Controlled groups (A) In general In the case of a controlled group of corporations, all corporations which are component members of such group shall be treated as 1 taxpayer. For purposes of the preceding sentence, the term “controlled group of corporations” has the meaning given to such term by subsection (a) of section 1563, except that “more than 50 percent” shall be substituted for “at least 80 percent” each place it appears in such subsection. (B) Controlled groups which include nonincorporated persons Under regulations prescribed by the Secretary, principles similar to the principles of subparagraph (A) shall apply to a group of persons under common control where 1 or more of such persons is not a corporation.
26 USC § 5061(e)(3)
None identified, default scope is assumed to be the parent (subpart E) of this section.