This document specifies two categories of method for the determination of the vinyl acetate (VAC) content of ethylene/vinyl acetate (EVAC) copolymer, for use in the designation of such copolymers according to ISO 21301-1. One category is referred to as “reference methods”, the other as “test methods”. The “reference methods” are used to calibrate the method used for the determination of the vinyl acetate content of ethylene/vinyl acetate copolymers. The “test methods” are other methods which can be used for the determination if they are calibrated using one of the reference methods described in Clause 4, provided they show a certain permissible repeatability.