(1)In respect of any expenditure of a capital nature incurred after the 28th day of February, 1966, [ Inserted by Act 20 of 1967, Section 13 (w.r.e.f. 1.4.1967).][but before the 1st day of April, 1998] [ Inserted by Act 21 of 1998, Section 12 (w.e.f. 1.4.1999).][, on the acquisition of patent rights or copyrights (hereafter, in this section, referred to as rights) used for the purposes of the business, there shall, subject to and in accordance with the provisions of this section, be allowed for each of the relevant previous years, a deduction equal to the appropriate fraction of the amount of such expenditure.Explanation. - For the purposes of this section,-(i)"relevant previous years" means the fourteen previous years beginning with the previous year in which such expenditure is incurred or, where such expenditure is incurred before the commencement of the business, the fourteen previous years beginning with the previous year in which the business commenced:Provided that where the rights commenced, that is to say, became effective, in any year prior to the previous year in which expenditure on the acquisition thereof was incurred by the assessee, this clause shall have effect with the substitution for the reference to fourteen years of a reference to fourteen years less the number of complete years which, when the rights are acquired by the assessee, have elapsed since the commencement thereof, and if fourteen years have elapsed as aforesaid, of a reference to one year;(ii)"appropriate fraction" means the fraction the numerator of which is one and the denominator of which is the number of the relevant previous years.
