Standard Air Pollution Classification Network: a Thesaurus of Terms

"The purpose of this thesaurus, is to present the special standardized terminology used for the storage of, and search for, information in the APTIG file. This second edition consists of this standardized terminology and illustrates the rules formulated for its use. The thesaurus should control the terminology and enable any inconsistencies to be resolved when indexers or searchers translate from the language of each document, or search request, into the conceptual system language presented here."