Exclusion of casual and non-recurring receipts preserves pre-amendment treatment in computation of total income for the transitional assessment year. Notwithstanding the Finance Act, 1972 amendments, any income characterised as casual and non recurring under the pre amendment clause (3) of section 10, as it stood immediately before 1 April 1972, shall be excluded from the computation of a person's total income for the previous year relevant to the assessment year commencing 1 April 1972.