beginning on or before the date of the enactment of this Act and can demonstrate, by providing copies of timely filed tax returns (including amended returns) or otherwise, that only one person claimed the deduction under section 199 of such Code in such taxable years with respect to the property described in the agreement, then the amendments made by this section shall apply to such taxable years of such persons. (c) No inference The amendments made by this section are intended as safe harbors and shall not be construed as adversely affecting the eligibility for a deduction under section 199 of the Internal Revenue Code of 1986 of any person who contracts with another person to manufacture, produce, grow or extract property described in subsection (c)(5) or (c)(6) of such section.