Large banks have sent feelers to the regulator to rethink the blanket rule on their uncovered foreign currency exposure. As rupee came under attack, the Reserve Bank of India (RBI) had imposed a $100 million uniform limit on all banks' net open position (NOP), which is the difference between a bank's foreign currency assets and liabilities at the end of each business day. In recent interactions with RBI, officials of big state-owned and private sector banks have suggested a dynamic regulation on the unhedged forex exposure, by linking an institution's NOP to its size and flows, two bankers told ET