ISO 25178-71:2017 defines Type S1 and Type S2 software measurement standards (etalons) for verifying the software of measuring instruments. It also defines the file format of Type S1 software measurement standards for the calibration of instruments for the measurement of surface texture by the areal method as defined in the areal surface texture chain of standards, chain link G.

NOTE Throughout ISO 25178-71:2017, the term "softgauge" is used as a substitute for "software measurement standard Type S1".