Defines basic symbols for use in the field of plain bearings, additional signs are also defined for use as superscripts and subscripts. The system is founded on characters of the Latin and Greek alphabets, Arabic figures and other signs, e.g. points, commas, horizontal lines or asterisks. For the purpose of international applicability, all symbols have been derived from English words. The present classification may be used in calculations and technological and geometrical determinations as well as in the quality assurance of plain bearings.