The thesaurus contains a documentation language devised for the purpose of analysing works, articles, reports and other documents relating to the problems of mass communication according to the particular medium to which they refer: books, the press, records, films, radio or television. While its main purpose is to characterize the information in a sufficiently precise manner to allow post-storage retrieval of the documents containing it, it has the secondary purpose of enabling queries to be expressed in a form which will match the information available.