This document establishes a system of designation for polyketone (PK) moulding and extrusion materials which may be used as the basis for specifications. Polyketone polymer chains are built up from regularly alternating olefinic units and keto groups. The olefinic units shall be randomly distributed ethylene and propylene. The types of polyketone plastics are differentiated from each other by a classification system based on appropriate levels of the designatory properties@ melting temperature@ melt mass-flow rate@ temperature of deflection under load and on information about the intended application and/or method of processing@ important properties@ additives@ colour@ fillers and reinforcing materials. The designation system is applicable to all polyketone terpolymers and blends. It applies to materials ready for normal use in the form of powder@ granules or pellets@ unmodified or modified by colourants@ fillers or other additives. It is not intended to imply that materials having the same designation give necessarily the same performance. This document does not provide engineering data@ performance data or data on processing conditions which may be required to specify a material. If such additional properties are required@ they are intended to be determined in accordance with the test methods specified in ISO 21970?2@ if suitable In order to designate a polyketone to meet particular specifications@ the requirements are to be given in data block 5 (see 4.1).