Establishing of a code system of designation for polyvinylchloride (PVC-U) moulding materials. The designation system is based on a standardized pattern. It consists of an (optional) description block, an identity block comprising the International Standard number and an individual item block which is subdivided into four data blocks with coded information: No. 1: identification of the polyvinylchloride by its symbol (PVC-U); No. 2: Position 1: Intended application or method of processing; position 2 to 4: Important properties, additives or supplementary information; No. 3: Designatory properties (coded property levels); No. 4: Fillers or reinforcing materials and their content. Designatory properties of polyvinylchloride are Vicat softening temperature, Charpy impact strength and modulus of elasticity. Examples of coded designations are given.