This guide describes good practice for the measurement and characterisation of smooth surface topography using coherence scanning interferometry (commonly referred to as vertical scanning white light interferometry). The guide is based on the measurement of the topography of semiconductors, epitaxial wafers and optical thin film coatings. However, the general guidelines described here can be applied to many flat, smooth surface topography measurements. For the purpose of this guide, the definition of a smooth surface is one that has an approximately random distribution of heights with a roughness (Sz) of less than 50 nm.