applicable 5-year period
(2) Applicable 5-year period For purposes of paragraph (1), the term “applicable 5-year period” means the 5-year period beginning on the date the notice taken into account for purposes of subsection (c)(1) was provided. For purposes of the preceding sentence, the rules of subsection (c)(2) shall apply.
26 USC § 7611(f)(2)
None identified, default scope is assumed to be the parent (subchapter A) of this section.