This International Standard is an Application Layer standard within the Open Systems Interconnection framework defined by ISO 7498. This standard defines the services for Interlibrary Loan. These services are provided by the use of the ILL protocol in conjunction with the supporting telecommunications service which may be a store-and-forward messaging service, such as that provided by the MOTIS Standards, ISO 10021-4 etc.; or a direct connection-mode service using ISO 8822 and ISO 8649. This standard does not specify individual implementations or products, nor does it constrain the implementation of entities and interfaces within a computer system. Computer systems may range from stand-alone workstations to mainframes. This standard is intended for use by libraries, information utilities such as union catalogue centres, and any other system which processes bibliographic information. These systems may participate in an interlibrary loan transaction in the role of requester (i.e. an initiator of ILL requests), responder (i.e. a provider of bibliographic material or information) and/or intermediary (i.e. an agent that acts on behalf of a requester to find suitable responders). Various interworking topologies are supported, ranging from simple two-party interactions to multiparty interactions. There is no requirement for conformance to this standard. Conformance is required only for the ILL protocol specification.