Buddhism 25 Religions of antiquity. Minor cults and religions 26 Judaism 27 Christianity 28 Islam 29 Modern spiritual movements 3 Social sciences 303 Methods of the social sciences 304 Social questions. Social practice. Cultural practice. Way of life (Lebensweise) 305 Gender studies 308 Sociography. Descriptive studies of society (both qualitative and quantitative) 311 Statistics as a science. Statistical theory 314/316 Society 314 Demography. Population studies 316 Sociology 32 Politics 33 Economics. Economic science 34 Law. Jurisprudence 35 Public administration. Government. Military affairs 36 Safeguarding the mental and material necessities of life 37 Education 39 Cultural anthropology. Ethnography. Customs. Manners. Traditions. Way of life 4 Currently Vacant This section is currently vacant. 5 Mathematics. Natural sciences 502/504 Environmental science. Conservation of natural resources. Threats to the environment and protection against them 502 The environment and its protection 504 Threats to the environment 51 Mathematics 510 Fundamental and general considerations of mathematics 511 Number theory 512 Algebra 514 Geometry 517 Analysis 519.1 Combinatorial analysis. Graph theory 519.2 Probability. Mathematical statistics 519.6 Computational mathematics. Numerical analysis 519.7 Mathematical cybernetics 519.8 Operational research (OR): mathematical theories and methods 52 Astronomy. Astrophysics. Space research. Geodesy 53 Physics 531/534 Mechanics 535 Optics 536 Heat. Thermodynamics. Statistical physics 537 Electricity. Magnetism. Electromagnetism 538.9 Condensed matter physics. Solid state physics 539 Physical nature of matter 54 Chemistry. Crystallography. Mineralogy 542 Practical laboratory chemistry. Preparative and experimental chemistry 543 Analytical chemistry 544 Physical chemistry 546 Inorganic chemistry 547 Organic chemistry 548/549 Mineralogical sciences. Crystallography. Mineralogy 55 Earth sciences. Geological sciences 56 Paleontology 57 Biological sciences in general 58 Botany 59 Zoology 6 Applied sciences. Medicine. Technology Class 6 occupies the largest proportion of UDC schedules. It contains over 44,000 subdivisions. Each specific field of technology or industry usually contains more than one special auxiliary table with concepts needed to express operations, processes, materials and products. As a result, UDC codes are often created through the combination of various attributes. Equally, some parts of this class enumerate concepts to a great level of detail e.g. 621.882.212 Hexagon screws with additional shapes. Including: Flank screws. Collar screws. Cap screws 60 Biotechnology 61 Medical sciences 611/612 Human biology 613 Hygiene generally. Personal health and hygiene 614 Public health and hygiene. Accident prevention 615 Pharmacology. Therapeutics. Toxicology 616 Pathology. Clinical medicine 617 Surgery. Orthopaedics. Ophthalmology 618 Gynaecology. Obstetrics 62 Engineering. Technology in general 620 Materials testing. Commercial materials. Power stations. Economics of energy