This part of ISO/IEC 24727 defines services as representations of action requests and action responses to be supported at the client-application service interface. The services are described in a programming-languageindependent way. This part of ISO/IEC 24727 is the application interface of the Open Systems Interconnection Reference Model defined in ISO/IEC 7498-1. It provides a high-level interface for a client-application making use of information storage and processing operations of a card-application as viewed on the generic card interface. This part of ISO/IEC 24727 does not mandate a specific implementation methodology for this interface.