Income tax rates and withholding rules establish category specific tax brackets, TDS rates and agricultural income computation methods. The First Schedule prescribes statutory income tax rates and surcharges for distinct classes of assessees, sets differential rates for deduction of tax at source on specified receipts distinguishing residents, non residents and types of payers, and supplies rates for calculating tax in special charging or advance tax situations. It also contains rules for computing net agricultural income by treating different agricultural receipts under specified heads of income, permitting certain deductions and loss set offs subject to temporal and constituency limitations, and conferring assessment powers to the Assessing Officer.