NATIONAL BANKING UNDER THE FEDERAL RESERVE SYSTEM for the purpose of conducting or settling accounts resulting from a transaction or transactions involving any one of the following: (a) The shipment of goods between the United States and any foreign country, or between the United States or any of its dependencies, or between foreign countries; (b) The shipment of goods within the United States, providing shipping docu- ments conveying security title are attached at the time of acceptance; | (c) The storage of readily marketable staples,’ providing the bill is secured at the time of acceptance by a warehouse receipt, or other such document con- veying security title. In order to be eligible, acceptances for any one customer in excess of 10 per cent. of the capital and surplus of the accepting bank must remain actually secured throughout the life of the acceptance. In the case of acceptances of member banks this security must consist of shipping documents, warehouse receipts or other such documents, or some other actual security growing out of the same transaction as the acceptance. Although a Federal Reserve Bank may legally rediscount an ac- ceptance having a maturity at the time of not more than 90 days, or six months in case of agricultural acceptance, it may decline to rediscount any acceptance the maturity of which is in excess of the usual or customary period of credit required to finance the underlying transaction or which is in excess of that period reasonably necessary to finance such transaction. Special conditions of eligibility for rediscount by the Federal Reserve Bank are laid down in greater detail by the Federal Reserve Board. 111 Bills of exchange, trade acceptances, and bankers’ acceptances purchased in the open market by the Federal Reserve Bank The Federal Reserve Banks may, under rules and regulations pre- scribed by the Federal Reserve Board, purchase and sell in the open market, at home or abroad, from or to domestic or foreign banks, firms, corporations, or individuals, bankers’ acceptances and bills of 18ee note, page 74. 79