600.0.4. For the purposes of section 600.0.3, where the fraction referred to in subparagraph c of the second paragraph of that section cannot be determined by a taxpayer in respect of a fiscal period of a partnership that ended before 28 February 2000, or includes 28 February 2000 or 17 October 2000, the fraction is deemed to be (a) where the fiscal period ended before or began before 28 February 2000, 3/4;
(b) where the fiscal period began after 27 February 2000 but before 18 October 2000, 2/3; and
(c) in any other case, 1/2.