All functions for steam/water properties start with STM then comes abbreviations for inputs needed and at last the output. Some examples are STMPTH needs P, pressure and T, temperature and calculates H, specific enthalpy, STMPHT needs P, pressure and H, specific enthalpy and calculates T, temperature. The same rule applies to functions for dry air, moist air and flue gases. Functions for dry and moist air start with Air and functions for flue gases start with Flue. All functions for dry/moist air need mc, moisture content. Therefore it has been omitted from the function's name. The same is with the flue gas functions all of them need the volumetric or mole fraction of the gases. Functions for screen hygrometer start with Screen and functions for sling hygrometer start with Sling . These functions calculate SH, specific humidity, RH, relative humidity, PS, percentage saturation and VWR, volumetric water ratio.