Universal Decimal Classification

  1. Macao (Macau). Aomen (Ao-men)
  2. Macedonia. Former Yugoslav Republic of Macedonia. Republika Makedonija
  3. Macedonian
  4. Macedonian language
  5. Macedonian literature
  6. Machine elements. Motive power engineering. Materials handling. Fixings. Lubrication
  7. Machine-readable documents
  8. Machines according to motive power, propulsive force. Source of energy of machine
  9. Machines and mechanical apparatus
  10. Macro-Chibchan languages
  11. Macromolecular materials. Rubbers and plastics
  12. Madagascar. Democratic Republic of Madagascar. Repoblikan'i Madagasikara
  13. Magmatic rocks. Igneous rocks
  14. Magnetism
  15. Magnetism. Electromagnetism
  16. Mahatmas. Gurus. Wise men
  17. Mahayana Buddhism. The great vehicle
  18. Main ingredients for the blending of drinks. Fruit and vegetable juices. Syrups. Liqueurs. Soft drinks
  20. Making and mending of clothes at home. Domestic dressmaking
  21. Malacca (Aslian) group
  22. Malawi. Republic of Malawi
  23. Malay (Bahasa Indonesia; Bahasa Malaysia)
  24. Malayo-Polynesian languages
  25. Malaysia. Federation of Malaysia. Persekutuan Tanah Malaysia
  26. Maldives. Republic of the Maldives. Divehi Rājjey ge Jumhuriyyā
  27. Male persons. Men
  28. Mali. Republic of Mali. République du Mali
  29. Malta. Republic of Malta. Repubblika ta' Malta
  30. Mammalia (Mammals)
  31. Mammalia. Fossil mammals
  32. Man's relation to god(s)
  33. Man-made fibres
  34. Man. Mankind. Humanity. Doctrinal anthropology
  35. Management
  36. Management activities
  37. Management agents. Mechanisms. Measures
  38. Management aspects of educational institutions
  39. Management conditions. Factors
  40. Management operations. Direction
  41. Management theory
  42. Manner of contest. Combative style. Strategy. Tactics
  43. Manufacture of coins and medals. Minting
  44. Manufactured mineral-based materials
  45. Manuscripts
  46. Manuscripts. Rare and remarkable works
  47. Mapuche (Mapudungun)
  48. Marathi
  49. Maritime canals. Ship canals
  50. Marketing of forest products. Economics of forest transport and the wood industries
  51. Marketing. Sales. Selling. Distribution
  52. Marks of ownership or origin
  53. Marriage and family
  54. Marsupialia (Marsupials)
  55. Martyrs
  56. Mascarene Islands
  57. Masonry and related building crafts
  58. Mass communication. Informing, enlightening of the public at large
  59. Material and equipment of naval forces. Protection and armament of vessels. Submarine defences
  60. Material bases of life. Biochemistry. Molecular biology. Biophysics
  61. Materials of mainly organic origin
  62. Materials testing. Commercial materials. Power stations. Economics of energy
  63. Materials, characteristics, processes and equipment
  64. Mathematical and applied linguistics. Phonetics. Graphemics. Grammar. Semantics. Stylistics
  65. Mathematical crystallography. Continuum theory of crystals
  66. Mathematical cybernetics
  67. Mathematical economics
  68. Mathematical linguistics
  69. Mathematical logic
  70. Mathematical programming
  71. Mathematics
  73. Mauritania. Islamic Republic of Mauritania. Mūrītāniyā. Al-Jumhūriyyah al-Islāmiyyah al-Mūrītāniyyah
  74. Mauritius. Republic of Mauritius. Repiblik Moris. République de Maurice
  75. Meals and mealtimes. Tableware
  76. Means of producing signs and scripts
  77. Measurement of geometric and mechanical quantities: instruments, methods and units
  78. Measurement of heat quantity. Calorimetry
  79. Measurement of weight, mass. Measurement of volume
  80. Measurement principles, methods, techniques. Instrumentation
  81. Measures against industrial and other nuisances
  82. Mechanical energy. Conservation of mechanical energy
  83. Mechanical engineering in general. Nuclear technology. Electrical engineering. Machinery
  84. Mechanical technology in general: processes, tools, machines, equipment
  85. Mechanical treatment for solidification of fuels. Briquetting
  86. Mechanics
  87. Mechanics of gases. Aeromechanics. Plasma physics
  88. Mediaeval art (Christian, Islamic art)
  89. Medical instruments and equipment in general
  90. Medical sciences
  91. Medicaments according to their origin
  92. Medicaments according to their principal action
  93. Medo-Persia
  94. Melanesia. States and regions of Melanesia
  95. Memory characteristics
  96. Memory system
  97. Memory units. Storage units
  98. Mental development and capacity. Comparative psychology
  99. Mercantile marine penal law. Penal and disciplinary regime in merchant navy
  100. Messiah(s)
  101. Metal arts
  102. Metallic compounds in general. Salts. Mineral compounds
  103. Metallurgy
  104. Metals
  105. Metals in general
  106. Metamorphic rocks
  107. Metaphysics
  108. Metaphysics of spiritual life
  109. Metatheria
  110. Meteorites
  111. Meteorology
  112. Methodology
  113. Methodology of history. Ancillary historical sciences
  114. Methodology of linguistics. Methods and means
  115. Methods of the social sciences
  116. Metrology. Weights and measures in general
  117. Mexico. Central American states. Caribbean territories
  118. Mexico. United Mexican States. México (Méjico). Estados Unidos Mexicanos
  119. Miao-Yao languages
  120. Microbial morphology
  121. Microbial physics, chemistry, metabolism, catabolism
  122. Microbial physiology
  123. Microbial techniques
  124. Microbiological industries. Science and technique of applied microbiology. Applied mycology
  125. Microbiology
  126. Micronesia. States and regions of Micronesia
  127. Middle levels of administration. Regional, provincial government. Regional authorities
  128. Middle period
  129. Middle period
  130. Military administration
  131. Military affairs generally
  132. Military affairs. Art of war. Military science. Defence. Armed forces
  133. Military and naval aviation. Air defence
  134. Military aviation. Flying corps. Air force
  135. Military engineering
  136. Military establishments: organization, functions
  137. Military justice and jurisdiction. Courts martial. Military tribunals
  138. Military penal law. Laws of armed land forces
  139. Mine drainage. Unwatering (dewatering)
  140. Mineral and metal fibres. Braiding materials. Rubber threads. Paper yarns
  141. Mineral oil technology. Technology of petroleum and allied products
  142. Mineral springs
  143. Mineralogical sciences. Crystallography. Mineralogy
  144. Mineralogy. Special study of minerals
  145. Mining
  146. Mining hazards, accidents and damage. Health protection and safety in mines
  147. Mining of specific minerals, ores, rocks
  148. Mining operations. Exploration, opening-up, development, working of mineral deposits
  149. Ministries for general business
  150. Minor aiming games. Children's miniature games
  151. Minor board games not dependent on chance
  152. Miscellanea. Polygraphies. Selections
  153. Miscellaneous organic chemical industries
  154. Mixe-Zoque languages
  155. Modern art movements (from late 19th century). Realism, impressionism and subsequent 20th century trends
  156. Modern Christian movements and churches
  157. Modern Indic languages
  158. Modern Indic languages
  159. Modern movements arising from Judaism
  160. Modern period
  161. Modern period
  162. Modern spiritual movements
  163. Moldova. Republic of Moldova. Republica Moldoveneasca
  164. Mollusca. Bryozoa. Brachiopoda
  165. Mollusca. Bryozoa. Brachiopoda
  166. Mon-Khmer languages
  167. Money. Monetary system. Banking. Stock exchanges
  168. Mongolia. State of Mongolia. Mongol Uls
  169. Mongolian languages
  170. Montenegro. Crna Gora
  171. Moral behaviour. Moral theology
  172. Moral philosophy. Ethics. Practical philosophy
  173. Morocco. Kingdom of Morocco. al-Maġrib. al-Mamlakâtu l-Maġribīyâ
  174. Mosaics
  175. Motor functions. Organs of locomotion. Voice. Integument
  176. Motoring. Motorcycling
  177. Mountaineering, climbing equipment. Swimming equipment
  178. Movable bridges
  179. Movables in general. Personalty
  180. Moving house. Removals
  181. Mozambique. Republic of Mozambique. República de Moçambique
  182. Multilingual. Polyglot
  183. Munda languages
  184. Museums. Permanent exhibitions
  185. Music
  186. Music teaching aids. Other music accessories
  187. Musical instruments and accessories
  188. Musical productions
  189. Musical sounds and perception
  190. Myanmar (Burma). Republic of the Union of Myanmar. Pyidaunzu Thanmăda Myăma Nainngandaw