S. 148A: Reassessment-Conducting inquiry, providing opportunity before issue of notice-Limitation-Alleged escapement on share transactions-Short-term capital gains below Rs. 50 lakhs-Notice issued beyond three years-In absence of material showing escapement exceeding threshold, notice held barred by limitation-Reassessment invalid. [S 147, 148, 148A(b), 148A(d), 149(1)(a), Art. 226]