The writing of the classification number in China Library Classification should follow: Basis for Classification of Books in Primary and Secondary Schools (4th Edition). Book classification is a tool for library classifiers to sort books. It is a classification system organized by many categories of different sizes according to their different attributes and certain principles. The order of categories at all levels is determined by symbols. The classification system of book classification is usually embodied in the form of tables. So it is also called the book classification table. A brief list of the classification structure of China Library Classification ── Primary and secondary school library edition 1, basic category A Marxism-Leninism, Mao Zedong Thought B philosophy C introduction to social science D politics, law E military F economy G culture, science, education, sports H language, writing I literature J art K history, geography N introduction to natural science O mathematical science and chemistry P astronomy, earth science Q biological science R medicine, health S agricultural science T industrial technology U transportation V aviation. Summary table (up to level 2) A Works of Marxism–Leninism, Mao Zedong Thought 1 Marx and Engels 2 Works of Lenin 3 Works of Stalin 4 Works of Mao Zedong 5 Works of Marx, Engels, Lenin, Stalin and Mao Zedong 7 Life and Biography of Marx, Engels, Lenin, Stalin and Mao Zedong 8 Marx, Leninism and Mao Zedong Thought studied B Philosophy 0 Philosophical Theory 1 World Philosophy 2 China Philosophy 3 Asian Philosophy 4 African Philosophy 5 European Philosophy 6 Oceania Philosophy 7 American Philosophy 80 Thinking Science 8 1 Logic 82 Ethics 83 Aesthetics 84 Psychology 9 Introduction to Atheism, Religion and Social Sciences C 1 Present Situation and Overview of Social Sciences 2 Colleges, Organizations and Conferences 3 Social Science Research Methods 4 Social Science Education and Teaching 5 Social Science Reference Books 8 Statistics 9/ Kloc-0/ Sociology 92 Demography 93 Management [94] System Theory (Systematics, Systems Engineering) 96 Talents D Politics, Law 0 Political Theory 1/3 *** Productive Political Parties 4 Workers, Peasants, Women's Movements and Organizations 45 Youth, Student Movements and Organizations 5/7 World Politics 8 Diplomacy, International Relations 9 Law E Military O Military Theory/ Military History 3 Military Technology 4 Synthetic Army 5 Army 6 Navy 7 Air Force 8 1 Strategic Missile Force 82 Public Security Force, Armed Police 83 Militia 84 Other Army F Economy 0 Political Economy 1 Economic Overview, Economic History, Economic Geography 2 Economic Planning and Management 3 Agricultural Economy 4 Industrial Economy 5 Transportation Economy 6 Posts and Telecommunications Economy 7 Trade Economy g Culture, Science, Education, Sports 0 Cultural Theory 1 Overview of cultural undertakings around the world 2 Information and knowledge dissemination 3 Science, scientific research 4 education 8 sports H language, writing 0 linguistics 1 Chinese 2 China minority languages 3 common foreign languages 4 language families, languages 9 international auxiliary languages I literature 0 literary theory 1 Complete Works of Literature 2 Poetry 3 Drama 4 Fiction 5 Reportage 6 Prose 69 Essay 7 Folk Literature 8 Children's Literature 9 Minority Literature 99 Religious Literature J Art 0 Art Theory 1 Art Overview World 2 Art 3 Comics, Children's Picture Books 4 Music, Dance 5 Drama, Movie, TV Art K History, Geography 0 History Theory 1 World History 2 China History 3/7 National History 8 1 Biography 85 Cultural Relics and Archaeology 89 Customs 9 Geography n General Theory of Natural Science 0 Theory and Methodology of Natural Science 1 Present Situation of Natural Science, Overview 2 Natural Science Institutions, Organizations and Conferences 3 Natural Science Research Methods 4 Natural Science Education and Teaching 5 Natural Science Series, Collected works and serial publications 6 natural science reference books 7 natural science literature retrieval reference books o mathematical science and chemistry 1 mathematics 3 mechanics 4 physics 6 chemistry 8 crystallography p astronomy, earth science 1 astronomy 2 surveying 3 geophysics 4 meteorology 5 geology 7 oceanography 9 physical geography q bioscience 1 General Biology 2 Cytology 3 Genetics 4 Biology 5 Biochemistry 6 Molecular Biology 8 1 Bioengineering 89 Environmental Biology 9 1 Paleontology 93 Microbiology 94 Botany 95 Zoology 96 Entomology 98 Anthropology R Medicine, Health 1 Preventive Medicine, Hygiene 2 Traditional Chinese Medicine 3 Basic Medicine 4 Clinical Medicine 5 Internal Medicine 6 Surgery 7 1 Obstetrics 72 Pediatrics 73 Oncology 74 Neurology and Psychiatry 75 Dermatology 76 Otolaryngology 77 Ophthalmology 78 Stomatology 78 Foreign Ethnic Medicine 8 Special Medicine 9 Pharmacy S Agricultural Science 1 Basic Agricultural Science 2 Agricultural Engineering 3 Agronomy (Agronomy) 4 Plant Protection 5 Crops 6 Gardening 7 Forestry 8 Animal Husbandry, Veterinary, Hunting, Silkworm, Bee 9 Aquatic Products, Fishery T industrial technology TB general industrial technology TD mining engineering TE oil and gas industry TF metallurgical industry TG metallurgy, metal technology TH machinery, instrument industry TJ weapons industry TK power engineering TL atomic energy technology TM electrical technology TN radio electronics, telecommunications technology TP automation technology, computing technology TQ chemical industry TS light industry, handicraft map construction science TV water conservancy project U transportation 1 Comprehensive transportation 2 Railway transportation 4 Road transportation 6 Waterway transportation 8 Air transportation v Aviation, Aerospace 1 Research and Exploration of Aviation and Aerospace Technology 2 Aviation 4 Aerospace (Aerospace) 7 Aviation, Aerospace Medicine x Environmental Science, Labor Protection Science (Safety Science) 1 Basic theory of environmental science 2 environmental comprehensive research 3 environmental protection management 4 disasters and their prevention and control 5 environmental pollution and its prevention and control 7 governance and comprehensive utilization 8 environmental quality evaluation and environmental monitoring 9 labor protection science (safety science) z comprehensive book 1 series 2 encyclopedia, quasi-book 3 dictionary 4 essays, complete works, anthologies, miscellaneous books 5 yearbooks, 6-month annual magazines, 8 bibliographies and books.