It has often been suggested that terms are not prone to variation. Moreover, many standardizing organizations and terminology textbooks take a prescriptive approach to term formation and use in which they disparage variation. However, we believe that variation is not due to arbitrariness or carelessness, but rather that it is well-motivated and useful in expert discourse. We hypothesize that multidimensional classification is one of the determining factors behind term choice and we present an empirical study of the influence of multidimensional classification on term use in which we examine variant terms in context in a one-million word corpus in the specialized subject field of optical scanning technology.