本标准定义了信息检索应用服务（第3节），并规定了信息检索应用协议（第4节）。服务定义描述了支持应用程序内功能的服务；这些服务由Z39支持。50号议定书。该描述既不指定也不限制计算机系统内的实现。协议规范包括协议控制信息的定义、交换该信息的规则，以及实现该协议所需满足的一致性要求。 本标准适用于支持信息检索服务的系统，以及信息服务、大学、图书馆和联合目录中心等组织，解决了连接问题- 面向对象，程序对程序的沟通。它不涉及与终端或通过其他物理媒体的信息交换。

This standard defines the Information Retrieval Application Service (section？3) and specifies the Information Retrieval Application Protocol (section？4). The service definition describes services that support capabilities within an application; the services are in turn supported by the Z39.50 protocol. The description neither specifies nor constrains the implementation within a computer system. The protocol specification includes the definition of the protocol control information, the rules for exchanging this information, and the conformance requirements to be met by implementation of this protocol. Intended for systems supporting information retrieval services, and for organizations such as information services, universities, libraries, and union catalogue centers, this standard addresses connection-oriented, program-to-program communication. It does not address interchange of information with terminals or via other physical media.