This Technical Specification specifies a reference dictionary for cutting items, together with their descriptive properties and domains of values, for use in cutting tool data representation. The reference dictionary contains — definitions and identifications of the classes of cutting items and their features, with an associated classification scheme, — definitions and identifications of the data element types that represent the properties of cutting items and their features, and — definitions and identifications of domains of values for describing those data element types. Each class, property or domain of values of this application domain constitutes an entry of the reference dictionary defined in this Technical Specification. It is associated with a computer-sensible and human-readable definition, and with a computer-sensible identification. Identification of a dictionary entry allows unambiguous reference to it from any application that implements the information model defined in ISO 13399-1. Definitions and identifications of dictionary entries are defined by means of standard data that consist of instances of the EXPRESS entity data types defined in the common dictionary schema, resulting from a joint effort between ISO TC184/SC4/WG2 and IEC SC3D, and in its extensions defined in ISO 13584-24 and ISO 13584-25. The following are within the scope of this Technical Specification: — standard data that represent the various classes of cutting items and cutting item features; — standard data that represent the various properties of cutting items and cutting item features; — standard data that represent domains of values used for properties of cutting items and cutting item features; — definitions of reference systems for cutting items and their properties; — one implementation method by which the standard data defined may be exchanged. NOTE 1 The implementation method by which the standard data defined in this Technical Specification may be exchanged is given in ISO 10303-21. The following are outside its scope: — applications where these standard data may be stored or referenced; — implementation methods other than the one defined by which the standard data may be exchanged and referenced; — information model for cutting tools; — definitions of classes and properties for tool items; — definitions of classes and properties for adaptive items; — definitions of classes and properties for assembly items and auxiliary items. NOTE 2 The information model for cutting tools is defined in ISO 13399-1. NOTE 3 The definitions of classes and properties for tool items, adaptive items, assembly items and auxiliary items are provided in ISO/TS 13399-3, 4 and 5 respectively. NOTE 4 Terms and definitions used in the compilation of this reference dictionary are provided in Clause 3. The main collection of the terms and their definitions in the reference dictionary is provided in Annexes B to D. Terms used to define the structure and contents of the dictionary are specified in ISO/TS 13399-100.