clause (i) may be assessed, or a proceeding in court with respect to such amount may be initiated without assessment, within 4 years after the date on which the return making the election under this subsection for such property was filed. . (2) Conforming amendment The table of sections for part VIII of subchapter B of chapter 1 is amended by inserting before the item relating to section 248 the following new item: Sec. 247. Contributions to Alaska Native Settlement Trusts. . (3) Permissive Amendments to Trust Agreements Establishing Settlement Trusts (A) In general Notwithstanding any provision of law, including any provision of the Alaska Native Claims Settlement Act ( 43 U.S.C. 1601 et seq.), Alaska State law, or the terms of any trust agreement of a Settlement Trust (as defined under section 3(t) of the Alaska Native Claims Settlement Act ( 43 U.S.C. 1602(t) )), the terms of any trust agreement of a Settlement Trust may, within the 1-year period following the date of the enactment of this Act, be amended as necessary to allow such Trust to make an election described in subsection (g) of section 247 of the Internal Revenue Code of 1986 (as added by paragraph (1)). (B) Amendment An amendment described in subparagraph (A) shall be enacted pursuant to one or more agreements between the Native Corporation that established the Settlement Trust and the trustees of such Trust and shall not require any vote by the beneficiaries of such Trust or the shareholders of such Native Corporation. (C) Registration statement Any Settlement Trust which was registered in accordance with Alaska State law prior to the date of the enactment of an amendment described in subparagraph (A) shall not be required to file a new or amended registration statement to reflect such amendment. (4) Effective date (A) In general The amendments made by this subsection shall apply to taxable years for which the period of limitation on refund or credit under section 6511 of the Internal Revenue Code of 1986 has not expired. (B) One-year waiver of