applicable percentage
(2) Applicable percentage defined For purposes of paragraph (1), the term “applicable percentage” means 35 percent reduced (but not below 20 percent) by 1 percentage point for each $2,000 (or fraction thereof) by which the taxpayer’s adjusted gross income for the taxable year exceeds $15,000.
Source
26 USC § 21(a)(2)
Scoping language
None identified, default scope is assumed to be the parent (subpart A) of this section.