This Recommendation | International Standard establishes definitions of terms and conventions for use by Recommendations | International Standards defining OSI-services within the scope of the Basic Reference Model of Open Systems Interconnection; specifies the application of these terms and conventions to the Recommendations | International Standards defining OSI-services within the Application Layer of the Basic Reference Model of Open Systems Interconnection; specifies the application of these terms and conventions to Recommendations International Standards defining (N)-services for Layers 1-6 of the Basic Reference Model of Open Systems Interconnection.