94-00 General reference works (handbooks, dictionaries, bibliographies, etc.)
94-01 Instructional exposition (textbooks, tutorial papers, etc.)
94-02 Research exposition (monographs, survey articles)
94-03 Historical (must also be assigned at least one classification number from Section 01)
94-04 Explicit machine computation and programs (not the theory of computation or programming)
94-06 Proceedings, conferences, collections, etc.
94Axx Communication, information
94Bxx Theory of error-correcting codes and error-detecting codes
94Cxx Circuits, networks
94D05 Fuzzy sets and logic (in connection with questions of Section 94) [See also 03B52, 03E72, 28E10]