Donation deduction cap limits charitable contribution deductions to the smaller of income-based threshold or fixed ceiling, excess ignored. Amendment substitutes sub section (4) to limit aggregate deductions for specified charitable contributions by ignoring the amount by which the aggregate exceeds the smaller of an income based threshold (ten percent of gross total income after specified reductions) and a fixed monetary ceiling; and inserts sub section (5A) to provide that any sum for which a deduction is allowed under this section shall not be deductible under any other provision for the same or any other assessment year.