<h1>Salary already taxed can't be treated as undisclosed income; 80-IB, 80P, 80HHC issues, four-year limitation on order rectification</h1> Courts held that salary already taxed at source cannot be treated as undisclosed block-year income and income below taxable limit cannot be taxed for late filing; rental receipts from leasing commercial property are income from house property, not business income, and fair market value fixation for capital gains is factual; complex manufacturing transforming raw material into distinct product qualifies for section 80-IB deduction; appeals lacking filed grounds may be dismissed and no question of law found; exemption under section 80P must be decided per assessment year and revenue need not disclose scrutiny reasons; development and service charges do not form part of export or total turnover for section 80HHC; additions from bank materials without opportunity to explain must be set aside; tribunal cannot rectify orders beyond four years.