26 U.S.C. § 7852 — Other applicable rules

(a) Separability clause. If a court finds that a provision of this title, or how it applies to some person or situation, is invalid, that doesn't affect the rest of the title or how that provision applies to other people or situations.

(b) Reference in other laws to Internal Revenue Code of 1939^*. If any other U.S. law or Executive order refers to a provision of the 1939 tax code, that reference is also read as pointing to the matching provision of this title — unless the law or order clearly says otherwise, or that reading would clash with what it obviously meant.

(c) Items not to be twice included in income or deducted. The same item — whether it's income, a deduction, a credit, or something else — cannot be counted both under a tax in subtitle A of this title and under chapter 1 or 2 of the 1939 tax code, unless the law clearly says or means otherwise.

(d) Treaty obligations.
(1) In general. When deciding how a treaty relates to a U.S. revenue law, neither one automatically wins just because it's a treaty or just because it's a law.
(2) Savings clause for 1954 treaties. This title, as it stood without any amendments made after August 16, 1954, does not apply in any situation where applying it would break a U.S. treaty obligation that was in effect on August 16, 1954.

(e) Privacy Act of 1974. Certain parts of the Privacy Act (subsections (d)(2), (3), and (4), and subsection (g) of section 552a of title 5) cannot be used, directly or indirectly, to help decide whether someone owes — or how much they owe — in tax, penalty, interest, fines, forfeitures, or other charges under this title.