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.
11 Logic <br /> 12 Mathematics <br /> 21 Astronomy, Astrophysics <br/> 22 Physics <br /> 23 Chemistry <br /> 24 Life Sciences <br /> 25 Earth and space science <br /> 31 Agricultural Sciences <br /> 32 Medical Sciences <br /> 33 Technological Sciences <br /> 51 Anthropology <br /> 52 Demography <br /> 53 Economic Sciences <br /> 54 Geography <br /> 55 History <br /> 56 Juridical Science and Law <br /> 57 Linguistics <br /> 58 Pedagogy <br /> 59 Political Science <br /> 61 Psychology <br /> 62 Sciences of Arts and Letters <br /> 63 Sociology <br /> 71 Ethics <br /> 72 Philosophy