Tribunal held that the assessee as a co-operative bank was bound by the Reserve Bank of India directives. According to such directives, the assessee had to invest certain amounts in Government securities and to hold the securities till maturity. In the process of acquisition, if there was any premium paid on the face value of the security, the loss had to be amortised. The instructions of the Board were applicable for determining the taxability of an assessee and if the securities acquired by the assessee were under the category held to maturity, the premium paid on acquiring such security was to be spread over the remaining period up to maturity and would be allowed to the assessee in each year. Those instructions were required to be applied to the securities held for trading as well as available for sale.  Accordingly the AO was to first determine the issue whether those securities were identifiable under the category “held for trading” or “available for sale”, and if so, allow depreciation. Otherwise, the Assessing Officer could decide the issue in accordance with law. (AY. 2011-12, 2012-13)