ISO/TR 19319:2013 describes: functions and their relevance to lateral resolution: point spread function (PSF), line spread function (LSF), edge spread function (ESF), modulation transfer function (MTF) and contrast transfer function (CTF), experimental methods for the determination of lateral resolution and parameters related to lateral resolution: imaging of a narrow stripe, sharp edge and square-wave gratings, physical factors affecting lateral resolution, analysis area and sample area viewed by the analyser in Auger electron spectroscopy and X-ray photoelectron spectroscopy.