Deduction for royalty and technical know how income allowed subject to approval and prescribed procedural conditions. Deduction for income characterised as royalty, commission, fees or other payments received by an Indian company for provision of technical know how or related services, limited to an allowance equal to forty per cent of such income where the agreement met approval requirements; 'provision of technical know how' encompassed transfer or licence of rights in patents, imparting information on use or working of such rights, use of such property, and imparting industrial, commercial or scientific knowledge, and the deduction was subject to procedural conditions and exclusions.