Abstract: The language of a rapidly developing science is dynamic and poses problems in the use of terminology standards. Where standards exist, the speed at which they become out of date discourages use. Where standards are lacking, users of the scientific literature suffer from the lack of consistency and precision in terminology. In this situation, abstracting and indexing services, which are involved in the storage of information for retrieval purposes, sometimes resolve the problem with a judicious mix of controlled vocabularies, and carefully managed uncontrolled vocabularies, thus establishing de facto standards within the organization. Techniques for the application of vocabulary control adopted by one large abstracting and indexing service are described, as is the manner in which vocabularies are kept up to date and maintained under editorial control.