Research expenditure deduction expanded: enhanced weighted deduction for approved scientific research, with certification and exclusion rules. A new sub-section (2B) provides a weighted deduction equal to one and one fourth times certified expenditure for approved scientific research (excluding capital expenditure on land or buildings). The deduction is exclusive of other specified deductions for the same expenditure or assets, bars duplicate asset deductions under other provisions, and any excess deduction is deemed wrongly made unless a completion certificate from the prescribed authority is furnished within one year of the programme completion period, with procedural consequences under the relevant assessment provision.