functional currency
(1) In general For purposes of this subtitle, the term “functional currency” means— (A) except as provided in subparagraph (B), the dollar, or (B) in the case of a qualified business unit, the currency of the economic environment in which a significant part of such unit’s activities are conducted and which is used by such unit in keeping its books and records.
Source
26 USC § 985(b)(1)
Scoping language
None identified, default scope is assumed to be the parent (subpart J) of this section.