26 U.S.C. § 6114

(a) In general Each taxpayer who, with respect to any tax imposed by this title, takes the position that a treaty of the United States overrules (or otherwise modifies) an internal revenue law of the United States shall disclose (in such manner as the Secretary may prescribe) such position— (1) on the return of tax for such tax (or any statement attached to such return), or (2) if no return of tax is required to be filed, in such form as the Secretary may prescribe. (b) Waiver authority The Secretary may waive the requirements of subsection (a) with respect to classes of cases for which the Secretary determines that the waiver will not impede the assessment and collection of tax.