Exemption under section 35AC: Government approves institutions and specifies eligible projects and deductible costs for three financial years. Central Government approves specified charitable and welfare institutions and, for each, specifies eligible projects or schemes together with estimated project costs and the maximum portion of those costs allowable as deductions under the tax exemption regime; the approvals and deduction caps operate for a fixed three year period in relation to three consecutive financial years, and subsequent notes record substitutions and an omission affecting table entries.