This SAE Aerospace Standard (AS) provides performance station designation and nomenclature systems for aircraft propulsion systems and their derivatives. The systems presented herein are for use in all communications concerning propulsion system performance such as computer programs@ data reduction@ design activities@ and published documents. They are intended to facilitate calculations by the program user without unduly restricting the method of calculation used by the program supplier. The list of symbols presented herein will be used for identification of input and output parameters. These symbols are not required to be used as internal parameter names within the engine subprogram.