ISO/IEC 21823-3:2021提供了物联网系统语义互操作性的基本概念，如ISO/IEC 21823-1的方面模型所述，包括:
–核心本体对语义互操作性的要求
–关于如何使用本体和开发特定领域应用程序的最佳实践和指导，包括需要考虑可扩展性和与外部本体的连接
–本体的跨领域规范和形式化，以提供现有本体的协调利用
–相关物联网本体，以及模块化、可扩展性、可重用性、可扩展性、与上层本体的互操作性等方面的特征和方法的比较研究
–展示语义互操作性必要性和需求的用例和服务场景。

ISO/IEC 21823-3:2021 provides the basic concepts for IoT systems semantic interoperability, as described in the facet model of ISO/IEC 21823-1, including:
– requirements of the core ontologies for semantic interoperability;
– best practices and guidance on how to use ontologies and to develop domain-specific applications, including the need to allow for extensibility and connection to external ontologies;
– cross-domain specification and formalization of ontologies to provide harmonized utilization of existing ontologies;
– relevant IoT ontologies along with comparative study of the characteristics and approaches in terms of modularity, extensibility, reusability, scalability, interoperability with upper ontologies, and so on, and;
– use cases and service scenarios that exhibit necessities and requirements of semantic interoperability.