The standard describes the measurement set-up and methods to evaluate X-ray optical systems. Methods to characterise geometric properties of X-rays are described as well as approaches for their spectral analysis. Coordinate systems for non-ambiguous description of the measurement set-up are defined. Positioning and detector systems suitable for the different measurement tasks are specified. An overview of common X-ray sources is given. The typical properties of the different X-ray sources relevant for their measurement are described.