Tax deduction under section 35AC: government notifies eligible institutions and projects, permitting specified deductible costs. Central government notifies specified charitable institutions and approves identified projects and estimated costs, specifying the maximum amount of such costs that may be allowed as a deduction under section 35AC. The notification lists thirty one institutions with project descriptions and cost caps, includes corpus fund specifications where applicable, and states that the approvals apply for a three year period commencing with the 2011-12 financial year; later substitutions to certain amounts are recorded.