Provides a firm basis for the clear and unambiguous definition of characteristic properties (data element types) of all elements of electrotechnical systems from basic components to subassemblies and full systems. Although originally conceived in the context of providing a basis for the exchange of information on electric/electronic components, may be used in areas outside the original conception such as assemblies of components and electrotechnical systems and subsystems. Provides for establishing a classification hierarchy and the allocation of applicable and relevant properties to each of the classes so established in order to describe fully the characteristics of objects belonging to that class. Provision is also made for definition of the terms used in classification. Facilitates the exchange of data describing electrotechnical systems through a defined structure for the information to be exchanged in a computer-sensible form. Closely associated with this part of IEC 61360 is IEC 61360-2. This part contains the information model, using the EXPRESS modelling language. Use of this information model allows dictionary information to be exchanged between different systems using the STEP Physical File Format as defined in ISO 10303-21.