IEC 61360-1:2017 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. This fourth edition cancels and replaces the third edition published in 2009. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:- support of advanced constructs such as- conditions and constraints,- blocks,- cardinality,- polymorphism,- generic and restricted enumerations, and- mapping;- extended list of data types;- harmonization with IEC 62656-1;- support of IEC TS 62720 and of coded units;- harmonization of semantic and administrative data among the various information objects;- use of UML for data modelling;- enhanced definitions and descriptions;- introduction of examples of higher level constructs such as block, cardinality, or polymorphism as guidance for the user of the IEC 61360 series.