the 20th World Congress of Soil Science in Jeju in 2014, the third edition. An update of the third edition was issued in 2015. Whereas the second edition was only suitable for naming soils, the third and the following edition can additionally be used for creating map legends. At the 22nd World Congress of Soil Science in Glasgow in 2022, the fourth edition was published. The 4th edition is an open access document under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. The WRB has two hierarchical levels (see below) and has in that sense a similar approach as the French référencial pédologique (1992, 1995, 2008). Contrary to that, the USDA soil taxonomy is strongly hierarchical and has six levels. The classification in WRB is based mainly on soil morphology (field and laboratory data) as an expression of pedogenesis. Another difference with USDA soil taxonomy is that soil climate is regarded only as a soil-forming factor and not as a soil characteristic. The WRB is not meant to replace national soil classification systems, which, for their area, may be more detailed than the WRB. WRB Working Group The WRB is edited by a working group of the International Union of Soil Sciences (IUSS). The current chair of the working group is Cezary Kabala (Wroclaw University of Environmental and Life Sciences, Poland, since 2022). The current vice-chair is Stephan Mantel (International Soil Reference and Information Centre, The Netherlands, since 2018). Chairs of the WRB working group and responsible first authors of the WRB editions are: Seppe Deckers (Belgium, 1st edition 1998), Erika Michéli (Hungary, 2nd edition 2006) and Peter Schad (Germany, 3rd edition 2014 and 4th edition 2022). The WRB working group has a homepage that is currently hosted by the Chair of Soil Science of the Technical University of Munich. It provides the following: the currently valid fourth edition of the WRB (2022) for download, the third edition (Update 2015) with the English original and the translations into Czech, French, Georgian, Polish, Russian, Slovene, and Spanish, an explanation of the system, soil profile photos of all RSGs, which may be downloaded and used if the author is accredited (additional photos can be found on the World of Soils page of the IUSS), the history of the WRB, the WRB leadership, information about past and