12. Substituted by the Finance (No. 2) Act, 1971, w.e.f. 1-4-1972. This topic was originally dealt with by section 85C which was inserted by the Finance Act, 1966, w.e.f. 1-4-1966. Section 80-O was inserted, in place of section 85C which was deleted by the Finance (No. 2) Act, 1967, w.e.f. 1-4-1968. Section 80-O was later on amended by the Finance Act, 1968, w.e.f. 1-4-1969.