Universal Decimal Classification

  1. Ibero-Romance / Ibero-Romanic languages
  2. Ibero-Romance languages
  3. Iceland. Republic of Iceland. Lýðveldið Ísland
  4. Icelandic
  5. Igneous, sedimentary and metamorphic petrology
  6. Igniters. Kindlers. Matches. Lighters
  7. Images. Pictorial documents. Graphic documents
  8. Immersed bodies (submerged bodies). Floating bodies
  9. Immunogenicity
  10. Imperialism. Imperialistic policy. Political expansionism
  11. In-port facilities. Docks. Wharfs. Quays. Installations and equipment
  12. Incunabula
  13. Independent administration of regions of a country. Ministries of regions
  14. India. Republic of India. Bhārat Gaṇarājya
  15. Indic languages
  16. Indic languages
  17. Indic literatures
  18. Indigenous languages of Canada, USA and Northern-Central Mexico
  19. Indigenous languages of western North American Coast, Mexico and Yucatan
  20. Individual branches of land and air forces
  21. Individual ethics. Human duties to oneself
  22. Individual natural languages
  23. Individual places of the ancient and modern world
  24. Individual polygraphies. Collected works of individual authors
  25. Individual spatial divisions and regional units
  26. Indo-China
  27. Indo-European languages
  28. Indo-European languages
  29. Indo-European languages of Europe
  30. Indo-European literature
  31. Indo-European peoples
  32. Indo-Iranian languages
  33. Indo-Iranian languages
  34. Indo-Iranian, Nuristani (Kafiri) and dead Indo-European languages
  35. Indo-Pacific (non-Austronesian) languages
  36. Indo-Pacific (non-Austronesian) languages. Australian languages
  37. Indo-Pacific (non-Austronesian) languages. Australian languages
  38. Indonesia. Republic of Indonesia. Republik Indonesia
  39. Indoor climate control. Heating. Ventilation. Air conditioning
  40. Indoor climate. Air conditioning. Heating. Ventilating
  41. Industrial and domestic arts and crafts. Applied arts
  42. Industrial microbiology. Industrial mycology. Zymurgy, fermentation industry. Beverage industry. Stimulant industry
  43. Industries based on macromolecular materials. Rubber industry. Plastics industry
  44. Industries based on various processable materials
  45. Industries, crafts and trades for finished or assembled articles
  46. Infantry: personnel, organization
  47. Inflammation. Irritation. Engorgement (hyperaemia). Mucous congestion
  48. Influence phase
  49. Information work. Advisory and consultancy services
  50. Initiators, primers for explosives. Detonators
  51. Inland navigable waterways. Canals. Canalized rivers
  52. Inland trade. Internal trade. Domestic trade
  53. Inland waters
  54. Inorganic chemistry
  55. Input, output and storage media
  56. Insecta (Hexapoda). Insects
  57. Insecta (Hexapoda). Insects. Entomology
  58. Insectivora (Insectivorous mammals)
  59. Installations and plant. Premises. Buildings, works, factories. Materials
  60. Installations for health and comfort in dwellings
  61. Instruction set architecture
  62. Instrument-making in general. Instrumentation. Measuring instruments and their manufacture. Balances. Weighing devices
  63. Instrumental music. Symphonic music. Grouping of instruments. Ensemble music
  64. Instruments and equipment
  65. Insurance. Communal provision through sharing of risk
  66. Intaglio and relief processes. Photogravure. Letterpress or relief plates (line and halftone blocks)
  67. Intaglio techniques
  68. Interference. Diffraction. Scattering by diffraction
  69. Interior decoration
  70. Interior layout: accommodation, installation, equipment for persons and freight
  71. Intermolecular forces
  72. Internal geodynamics (endogenous processes)
  73. International arbitration. International adjudication, jurisdiction
  74. International blocs. Tension, conflict
  75. International criminal law
  76. International economy generally. International economic relations. Global economy
  77. International finance
  78. International law
  79. International private law. Conflict of laws
  80. International relations. World, global politics. International affairs. Foreign policy
  81. Internationalism. International movements, objectives
  82. Interplanetary medium. Comets. Meteors. Meteorites
  83. Interstellar medium. Galactic nebulae
  84. Introduces non-UDC notation (asterisk). Table 1h
  85. Invertebrata
  86. Invertebrata in general
  87. Iran. Islamic Republic of Iran. Jomhuri-ye Eslāmi-ye Irān
  88. Iranian languages
  89. Iraq. Republic of Iraq. Jumhūriyat Al-Irāq. Komara Îraqê
  90. Ireland. Republic of Ireland. Éire
  91. Irish
  92. Ironmongery. Hardware. Locksmithing. Bottling. Lamps. Heating appliances
  93. Irregularities in crystals
  94. Islam
  95. Islands north of Madagascar
  96. Isolated Islands of the Pacific Ocean
  97. Isolated, unclassified Central and South American indigenous languages
  98. Israel. State of Israel. Medīnat Yisrā'el. Dawlat Isrā'īl
  99. Issues in biotechnology
  100. Italia. Ancient Rome and Italy
  101. Italian
  102. Italian language
  103. Italian literature
  104. Italic languages
  105. Italic languages
  106. Italo-Romance / Italo-Romanic languages
  107. Italo-Romance languages
  108. Italy. Republic of Italy. Republica Italiana