As part of an effort to formulate a list of principles underlying subject heading languages used in various subject access systems throughout the world, IFLA's Lisbon Satellite Meeting reviewed a broad spectrum of national systems and considered current issues in their development.

By examining programs developed in Brazil, Canada, Croatia, France, Germany, Poland, Portugal, Spain, the U.K., and the U.S., the papers help to identify which principles each system considers fundamental and implicit and which had to be stated explicitly in usage instructions or subject heading codes. More general topics such as "International Tendencies in Terminology and Indexing" were also addressed.