Deduction under section 35AC: approved institutions and their eligible projects with capped deductible costs and validity. Notification under the Explanation to section 35AC approves specified institutions and, for each, identifies the eligible project or scheme, states the estimated cost and sets the maximum portion of that estimated cost that may be allowed as a deduction; it covers projects ranging from health and education to housing and sports, and prescribes differing deductible ceilings and prescribed assessment-year validity periods for the approvals.