UNESCO Nomenclature (more properly UNESCO nomenclature for fields of science and technology) is a system developed by UNESCO for classification of research papers and doctoral dissertations. There are three versions of the system, offering different levels of refinement through 2-, 4-, and 6-digit codes.
See also
External links
The article covering the full 6-digit nomenclature is incomplete in this English-language edition of Wikipedia but may be found in the Spanish-language edition at es:Clasificación Unesco 6 dígitos.