The objective of this Recommendation is to analyse identifiers in existing technologies for the Internet of things (IoT) services@ and describe the requirements of the IoT identifier@ common characteristics of the IoT identifier@ and the reference model of the IoT identifier. This Recommendation describes the requirements and common characteristics of the IoT identifier for the IoT services. The scope of this Recommendation includes: ?C analysis of identifiers in existing technologies@ ?C common characteristics of the IoT identifier@ ?C requirements of the IoT identifier@ ?C reference model of the IoT identifier.