Deduction of tax at source from salary: application of prescribed slab rates, capped contribution deductions, and surcharge rules. Deduction of tax at source for financial year 1972-73 applies to salary income paid on or after April 1, 1972, at the rates in Part III of the First Schedule to the Finance Bill, 1972; no deduction is made unless estimated salary exceeds the specified threshold. Disbursing officers must allow prescribed deductions including capped qualifying contributions for provident fund and life insurance, standard monthly travel deductions varying by conveyance status (not available where conveyance allowance is paid), and adjust for profession tax on proof; charitable donations and expenditure on books are excluded from withholding. Rounding rules, surcharge computation with marginal relief, illustrative examples, and penal liability for failure to deduct or pay are provided.