ISO/TS 13399-204:2016 specifies a concept for the design of cutting items, limited to any kind of replaceable inserts for reaming, using related properties and domains of values. ISO/TS 13399-204:2016 specifies a common way of designing simplified models that contain the following: - definitions and identification of the design features of replaceable inserts for reaming, with a link to the properties used; - definitions and identification of the internal structure of the 3D model that represents the features and the properties of replaceable inserts for reaming; The following are outside the scope of this part of ISO 13399: - applications where these standard data may be stored or referenced; - creation and exchange of simplified 3D models for cutting tools; - creation and exchange of simplified 3D models for tool items; - creation and exchange of simplified 3D models for other cutting items not described in this part of ISO 13399; - creation and exchange of simplified 3D models for adaptive items; - creation and exchange of simplified 3D models for assembly items and auxiliary items.