This document specifies procedures for the determination of the total scattering by coated and uncoated optical surfaces. Procedures are given for measuring the contributions of the forward scattering and backward scattering to the total scattering of an optical component. This document applies to coated and uncoated optical components with optical surfaces that have a radius of curvature of more than 10 m. Measurement wavelengths covered by this document range from the ultraviolet above 250 nm to the infrared spectral region below 15 ¼m. For measurements in the deep ultraviolet between 190 nm to 250 nm, specific methods have to be considered and are described. Generally, optical scattering is considered as neglectable for wavelengths above 15 ¼m.