This Technical Report describes: a) Functions and their relevance to lateral resolution: 1) Point spread function (PSF) — see 4.1.1 2) Line spread function (LSF) — see 4.1.2 3) Edge spread function (ESF) — see 4.1.3 4) Modulation transfer function (MTF) — see 4.1.4 5) Contrast transfer function (CTF) — see 4.1.5. b) Experimental methods for the determination of lateral resolution and parameters related to lateral resolution: 1) Imaging of a narrow stripe — see 4.2 2) Imaging of a sharp edge — see 4.3 3) Imaging of square-wave gratings — see 4.4. c) Physical factors affecting lateral resolution, analysis area and sample area viewed by the analyser in Auger electron spectroscopy and X-ray photoelectron spectroscopy — see Clauses 5 and 6.