This European Standard specifies the notation and symbols that are to be used for the description of testing and test results on the class of materials described as advanced technical ceramics, including powders, monolithic ceramics, ceramic coatings and ceramic matrix composites. It sets the rules for writing the symbols and quantities which characterize the mechanical and thermal properties of these materials. In particular regard to ceramic matrix composites with continuous reinforcements, definitions are given for the notations to be used for the mutually perpendicular directions 1, 2, 3 of reinforcement.