This part of IEC 61360 specifies principles for the definition of the properties and associated attributes and explains the methods for representing verbally defined concepts with appropriate data constructs available from IEC 61360-2. It also specifies principles for establishing a hierarchy of classification from a collection of classes, each of which represents a technical concept in the electrotechnical domain or a domain related to electrotechnology. The use of this document facilitates the exchange of technical data through a defined structure for the information to be exchanged in a computer-sensible form. Each property to be exchanged has an unambiguously defined meaning and consistent naming, where relevant a defined value list, a prescribed format and defined units of measure for all quantitative values. There is also provision for: a) control of changes to definitions of the properties through version and revision numbers; b) inclusion of notes and remarks to clarify and help in the application of the definitions; c) indication of the sources of definitions and value lists; d) associated figures and formulae. NOTE IEC TCs and SCs, or other organizations can take this document as a basis for the development of their own dictionaries. Out of scope of this document are subjects concerning the information technology infrastructure such as: security; database locking mechanisms; access rights management.