Establishes a designation system for poly(methyl methacrylate) (PMMA) moulding and extrusion materials which may be used as the basis for specifications. The types of poly(methyl methacrylate) plastics are differentiated from each other by a classifikation system based on cell codes for apprpriate levels of the designatory properties. The designatory properties are Vicat softening point, melt flow rate and viscosity number (optional). Additional codes are given for information about intended application, method of processing and important properties, additives, colour and fillers. Examples for coded designations are given.