Technical Report is based on experience gained in the standardization of two major areas in information processing. One area covers programming languages. The other area is composed of the services necessary to an application program to achieve a goal. The services are divided into coherent groups, each referred to as a SYSTEM FACILITY, that are accessed through a FUNCTIONAL INTERFACE. The specification of a system facility, referred to as a FUNCTIONAL SPECIFICATION, defines a collection of SYSTEM FUNCTIONS, each of which carries out some well-defined service.