Security is the process by which a creditor obtains an extra source for the repayment of his debt. In the financial context, it is an essential part of what may loosely be described as the enforcement of claims. This paper will seek to identify some of the main features of security in the light of current international trends. The subject is of interest to central bankers in their capacity as custodian of their countries’ financial systems. It is not proposed to enter into the debate as to whether security is necessary, desirable, or efficient.2 It is true that much lending is unsecured. Markets have sprung up to provide ready sources of unsecured credit, such as the commercial paper market. However, lenders like security, if they can get it, and this is the commercial reality of the situation.