本国际标准定义了形式化描述技术LOTOS的语法和语义。LOTOS通常用于分布式并发信息处理系统的形式化描述。具体而言，LOTO可用于正式描述ISO 7498中描述的开放系统互连（OSI）体系结构各层的服务定义和协议规范，以及相关标准，以及OSI协议和/或OSI功能实现的一致性测试。它还可以应用于其他分布式系统的形式化描述，如电话交换网络。

This International Standard defines the syntax and semantics of the Formal Description Technique LOTOS. LOTOS is in general used for the formal description of distributed, concurrent information processing systems. In particular LOTOS can be used to describe formally the service definitions and protocol specifications of the layers of Open Systems Interconnection (OSI) architecture described in ISO 7498, and related standards, and conformance tests for implementations of OSI protocols and/or OSI functions. It can also be applied for the formal description of other distributed systems, such as telephone switching networks.