细化OSI基本参考模型（ITU-T Rec.X.200/ISO/IEC 7498-1）中包含的应用层的描述。提供一个框架，用于协调现有和未来应用层建议和标准的开发。由应用层建议和标准提供以供参考。其目的是促进采用连贯和模块化的方法来构建应用层行为的规范。

Refines the description of the application layer contained in the basic reference model for OSI (ITU-T Rec. X.200 / ISO/IEC 7498-1). Provides a framework for coordinating the development of existing and future application layer recommendations and standards. Is provided for reference by application layer recommendations and standards. The purpose is to facilitate a coherent and modular approach to the structuring of specifications for application layer behaviour.