| HyPr | Hydrological Processes | In English | → Serial publications, periodicals → Hydrology |
| HZ | Historische Zeitschrift | In German | → Serial publications, periodicals → History |
| HZ | Hooge Zwaluwe | In Dutch | → Organizations and associations → Sport, physical exercises |
| HZC | Harlingen Zeevaartschool Combinatie | In Dutch | → Organizations and associations → Education → Sport, physical exercises |
| HZVV | Hoogeveense Zaterdag Voetbal Vereniging | In Dutch | → Organizations and associations → Football and rugby |
| I+D | Investigación y Desarrollo = R&D | Recherche et développement | In French = F&E | Forschung und Entwicklung | In German = R&D | Research and Development | In English = R&S | Ricerca e Sviluppo | In Italian = P&D | Pesquisa e Desenvolvimento | In Portuguese = O&O | Onderzoek en Ontwikkeling | In Dutch = FoU | Forsøk og Utvikling | In Norwegian |
In Spanish | → Research policy → Engineering, technology |
| I3C | Internet Créatif, Coopératif et Citoyen | In French | → Internet |
| I3S | (Laboratoire d')Informatique, Signaux et Systèmes de Sophia Antipolis | In French | → Research institutes → Computer science → Telecommunications |
| IA | Interface Agreement | In English | → Human-computer interaction |
| IA | Intelligència artificial = AI | Artificial Intelligence | In English = AI | Artificiële Intelligentie | In Dutch = KI | Kunstmatige Intelligentie | In Dutch = VI | Vještačka inteligencija | In Bosnian = KI | Künstliche Intelligenz | In German = AI | Artefarita Inteligenteco | In Esperanto = IA | Intelligence Artificielle | In French |
In Catalan | → Artificial intelligence |
| IA | Intelligence Artificielle = AI, KI, VI (look above) |
In French | → Artificial intelligence |
| ÍA | Íþróttabandalag Akraness (www.ia.is) | In Icelandic | → Organizations and associations → Sport, physical exercises |
| IA&A | Ingenieria aeronáutica y astronáutica | In Spanish | → Serial publications, periodicals → Aeronautics, aircraft → Spaceflight engineering, astronautics |
| IAA | International Aerospace Abstracts | In English | → Serial publications, periodicals → Astronomy → Aeronautics, aircraft → 6297 |
| IAA | International Association for Assyriology | In English | → Associations → Language, linguistics, literature → Archeology |
| IAAO | Islamic Arts and Architecture Organization (www.islamicart.com) | In English | → Organizations and associations → Islam → Arts |
| IAAO | International Association of Assessing Officers (www.iaao.org) | In English | → Associations |
| IABA | Inter-American Bar Association (www.iaba.org) | In English | → Associations → Law, jurisprudence |
| IABC | International Association of Business Communicators | In English | → Organizations and associations → Economics |
| IABEM | International Association for Boundary Element Methods | In English | → Associations → Mathematics |
| IABO | Internacia Asocio de Bibliistoj kaj Orientalismoj | In Esperanto | → Associations → Christianity |
| IABS | International Association of Buddhist Studies | In English | → Associations → Buddhism |
| IACD | Institute of Asian Culture and Development | In English | → Research institutes → Civilization, culture, progress → Area studies |
| IACL | International Association of Chinese Linguistics | In English | → Associations → Linguistics |
| IACNDR | Inter-American Committee on Natural Disaster Reduction = CIRDN | Comité Interamericano para la Reducción de los Desastres Naturales | In Spanish = CIRDN | Comitê Interamericano sobre a Redução de Desastres Naturais | In Portuguese |
In English | → Organizations and associations → Natural disasters |
| IACR | International Association for Cryptologic Research (www.iacr.org) | In English | → Associations → Mathematics → Telecommunications |
| IACS | Inter-Asia Cultural Studies Society | In English | → Organizations and associations → Civilization, culture, progress → Area studies |
| IACW | Inter-American Commission of Women (www.oas.org/cim/) = CIM | Comisión Interamericana de Mujeres | In English = CIF | Commission Interaméricaine des Femmes | In French = CIM | Comissão Interamericana de Mulheres | In Portuguese |
In English | → Organizations and associations → Feminism |
| IACW | International Association of Crime Writers = AIEP | Asociación Internacional de Escritores Policiácos | In Spanish |
In English | → Associations → Literature → Criminology |
| IAD | Internacia Asocio pri Disvolvado |
In Esperanto | → Associations → International relations |
| IAD | Interface Agreement Document | In English | → Human-computer interaction |
| IAD | Interface Analysis Document | In English | → Human-computer interaction |
| IAdEM | Internacia Asocio de Esperantistaj Matematikistoj | In Esperanto | → Associations → Mathematics |
| IadEn | Iadernaia Energiia = IadEN | ядерная энергия | In Russian |
In Russian | → Serial publications, periodicals → Nuclear, atomic, and molecular physics → Nuclear technology |
| IadEN | ядерная энергия = IadEn (look above) |
In Russian | → Serial publications, periodicals → Nuclear, atomic, and molecular physics → Nuclear technology |
| IAE | Institut d'Administration des Entreprises | In French | → Management → Economics |
| IAEA | Internacia Agrikultura Esperanto-Asocio | In Esperanto | → Associations → Agricultural sciences |
| IAESM | IEEE (Institute of Electrical and Electronics Engineers) Aerospace Electronic Systems Magazine | In English | → Serial publications, periodicals → Electronics → Spaceflight engineering, astronautics |
| IAESTE | International Association for the Exchange of Students for Technical Experience (www.iaeste.org) | In English | → Associations → Higher education, universities → Applied sciences, technology |
| IAF | Internationales Afrikaforum | In German | → Organizations and associations |
| IAF | Irish Arts Foundation | In English | → Foundations → Arts |
| IAF | Industrial Areas Foundation | In English | → Foundations → Industry, industrial policy |
| IAF | International Association of Facilitators | In English | → Associations |
| IAF | Internet Access Facilities | In English | → Internet → Telecommunications |
| IAF | Institut für angewandte Forschung | In German | → Research policy |
| IAF | Inter-American Foundation | In English | → Foundations |
| IAF | Interessengemeinschaft Ausbildung im Finanzbereich | In German | → Organizations and associations → Finance → Education |
| IAF | International Astronautical Federation | In English | → Organizations and associations → Spaceflight engineering, astronautics |
| IAF | International Apparel Federation | In English | → Organizations and associations |
| IAF | International Aikido Federation | In English | → Organizations and associations → Entertainment |
| IAGC | Institute of Applied Genetics and Cell Biology = IAGZ | Institut für Angewandte Genetik und Zellbiologie | In German |
In English | → Research institutes → Genetics → Cytology |
| IAGZ | Institut für Angewandte Genetik und Zellbiologie = IAGC (look above) |
In German | → Research institutes → Genetics → Cytology |
| IAH | Interface Attachment Hardware | In English | → Hardware → Human-computer interaction |
| IAH | International Association of Hydrogeologists | In English | → Associations → 5325 → Hydrology |
| IAHA | International Association of Historians of Asia | In English | → Associations → History |
| IAHR | International Association of Hydraulic Engineering and Research | In English | → Associations → Environmental technology, water supply, waste management |
| IAHS | International Association of Hydraulical Sciences | In English | → Associations → Environmental technology, water supply, waste management |
| IAI | Institut Africain d'Informatique | In French | → Specialized or (poly)technical colleges → Computer science |
| IAIK | Institut für Angewandte Informationsverarbeitung und Kommunikationstechnologie (www.iaik.tugraz.at) | In German | → Computer science → Telecommunications |
| IAIN | International Association of the Navigation Institutes | In English | → Associations → Geodesy, cartography → Vehicle engineering |
| IAL | International Association for Lichenology | In English | → Organizations and associations → Botany |
| IALANA | International Association of Lawyers Against Nuclear Arms | In English | → Associations → Law, jurisprudence → Nuclear technology → Applied sciences, technology |
| IALS | International Association of Literary Semantics | In French | → Associations → Literature |
| IAM | Information Asset Management | In English | → Management |
| IAM | International Association of Machinists | In English | → Associations → Mechanical engineering |
| IAN | Institutional Area Network | In English | → Networks, communication |
| IANIS | Innovative Actions Network for the Information Society | In English | → Computer science → Telecommunications |
| IANOR | Institut algérien de normalisation | In French | → Standardization |
| IANT | International Advances in Nondestructive Testing | In English | → Serial publications, periodicals → Engineering, technology |
| IAO | Ingénierie Assistée par Ordinateur | In French | → Computer-based techniques → Engineering, technology |
| IAO | Institut für Arbeitswirtschaft und Organisation (www.iao.fraunhofer.de) | In German | → Research institutes → Labour, labour economics |
| IAPM | IEEE (Institute of Electrical and Electronics Engineers) Antennas Propagation Magazine | In English | → Serial publications, periodicals → Telecommunications |
| IAPO | International Alliance of Patients' Organizations (www.patientsorganizations.org) | In English | → Organizations and associations → Medicine |
| IAPPP | International Amateur-Professional Photoelectric Photometry Communications | In English | → Serial publications, periodicals → Physics |
| IAPS | Independent Association of Prep Schools | In English | → Associations → Education |
| IAPS | International Association of Pastel Societies | In English | → Associations |
| IAPS | International Association for the Philosophy of Sport | In English | → Associations → Philosophy, psychology → Sport, physical exercises |
| IAPS | International Association for People-environment Studies | In English | → Associations → Nature and society |
| IAPS | International Association of Physics Students | In English | → Associations → Education → Physics |
| IAPS | International Association of Patristics Studies = AIEP | Association Internationale des Études Patristiques | In French |
In English | → Associations → Archeology → Roman catholic church |
| IARC | International Agency for Research on Cancer | In English | → Organizations and associations → Oncology |
| IAS | International Association of Sufism | In English | → Associations → Islam |
| IAS | Islamic Academy of Sciences | In English | → Academies → Islam → Mathematics and natural sciences |
| IAS | International Accounting Standards | In English | → Standardization → Commercial law → Accounting |
| IAS | Identification, Authentification et Signature | In French | → Computer science → Telecommunications |
| IAS | Interface d'Authentification Serveur | In French | → Networks, communication → Telecommunications |
| IAS | Indian Academy of Science | In English | → Serial publications, periodicals → Academies → Mathematics and natural sciences |
| IAS | Impact Assessment Sheet | In English | → Management |
| IASB | International Accounting Standards Board | In English | → Standardization → Commercial law → Accounting |
| IASCF | International Accounting Standards Committee Foundation | In English | → Foundations → Standardization → Commercial law → Applied sciences, technology |
| IASON | In Aangename Samenwerking Overwinning Nastreven | In Dutch | → Organizations and associations → Sport, physical exercises |
| IASP | Indian Association for the Study of Population | In English | → Associations → Demography |
| IASP | International Association of Science Parks | In English | → Associations → Museums → Mathematics and natural sciences |
| IASS | International Association of Sanskrit Studies | In English | → Associations → Language, linguistics, literature |
| IASS | International Association for Semiotic Studies = AIS | Association Internationale de la Sémiotique | In French |
In English | → Associations → Semiotics |
| IASSI | Indian Association of Social Science Institutions | In English | → Associations → Social sciences |
| IASSP | IEEE (Institute of Electrical and Electronics Engineers) ASSP Magazine | In English | → Serial publications, periodicals → Software |
| IASTAM | International Association for the Study of Traditional Asian Medicine | In English | → Associations → 6158 |
| IATA | International Air Transport Association | In English | → Associations → Transport and postal services |
| IATC | International Association of Teachers of Czech | In English | → Associations → Education → Language, linguistics, literature |
| IATIS | International Association for Translation and Intercultural Studies | In English | → Associations → Linguistics |
| IATSE | International Alliance of Theatrical Stage Employees and Moving Picture Machine Operators | In English | → Organizations and associations → Cinema, movies → Theatre |
| IATSS | International Association of Traffic and Safety Sciences | In English | → Associations → Transport and postal services |
| IAU | International Astronomical Union | In English | → Organizations and associations → Astronomy |
| IAUC | International Astronomical Union Circular | In English | → Serial publications, periodicals → Astronomy |
| IAUNRC | Inner Asian and Uralic National Resource Center | In English | → Libraries → Area studies |
| IAUPL | Internacia Asocio de Universitataj Profesoroj kaj Lekciistoj | In Esperanto | → Associations → Higher education, universities |
| IAUT | Transactions of the International Astronomical Union | In English | → Serial publications, periodicals → Astronomy |
| IAVCEI | International Association of Volcanology and Chemistry of the Earth's Interior (www.iavcei.org) | In English | → Associations → 55121 → Geochemistry |
| IB | Institut für Bodenforschung (www.boku.ac.at/boden/) | In German | → Research institutes → Agricultural sciences |
| IBA | International Bar Association (www.ibanet.org) | In English | → Associations → Law, jurisprudence |
| IBA | Institute for Biomedical Aging Research | In English | → Research institutes → Biological sciences → Medicine |
| IBAS | Indonesian Business Association of Shanghai | In English | → Associations → Economics |
| IBC | Indian Books Centre | In English | → Libraries |
| IBC | Itteren Borgharen Combinatie | In Dutch | → Organizations and associations → Sport, physical exercises |
| IBE | International Bureau for Epilepsy (www.ibe-epilepsy.org) | In English | → Organizations and associations → Neurology |
| IBEC | Irish Business and Employers Confederation | In English | → Organizations and associations → Labour, labour economics → Economic policy |
| IBEW | International Brotherhood of Electrical Workers | In English | → Organizations and associations → Electrical engineering |
| IBISC | Informatique, Biologie Intégrative et Systèmes Complexes | In French | → Computer science → Biological sciences |
| IBL | Institut de Biologie de Lille | In French | → Research institutes → Biological sciences |
| IBM | International Business Machines | In English | → Computer science |
| IBM | International Business Machines (Corporation) | In English | → Hardware |
| IBMG | Internationales Büro für Maß und Gewicht (www.bipm.org) = BIPM | Bureau International des Poids et Mesures | In French = BIPM | Bureau Internacional de Pesos e Medidas | In Portuguese = BIPM | Buroo Internacia pri Pezoj kaj Mezuroj | In Esperanto |
In German | → Standardization |
| IBMJ | IBM Journal Research Development | In English | → Serial publications, periodicals → Computer science |
| IBN | Institute of Bioengineering and Nanotechnology | In English | → Research institutes → Biotechnology |
| IBN | Institut Belge de Normalisation = BNI | Belgisch Instituut voor Normalisatie | In Dutch |
In French | → Standardization |
| IBO | Associazione Italiana Soci Costruttori | In Italian | → Associations |
| IBSH | Informational Bulletin of the Southern Hemisphere | In English | → Serial publications, periodicals → Earth sciences |
| IBT | International Brotherhood of Teamsters | In English | → Organizations and associations |
| IBT | Internationaler Bund der Tierversuchsgegner (www.tierversuchsgegner.at) | In German | → Organizations and associations → Nature → Pharmacology, toxicology |
| ÍBV | Íþróttabandalag Vestmannaeyja (www.ibv.is) | In Icelandic | → Organizations and associations → Sport, physical exercises |
| IBVS | Informational Bulletin on Variable Stars | In English | → Serial publications, periodicals → Astronomy |
| IC | Intercomputer Communication | In English | → Networks, communication |
| IC | Intercommunications | In English | → Networks, communication → Telecommunications |
| IC | Islamic Culture | In English | → Civilization, culture, progress → Linguistics → Literature |
| ICA | Intelligent Communicating Agent | In English | → Computer science |
| ICAAD | Interactive Computer-Aided Analysis and Design | In English | → Computer-based techniques |
| ICAANE | International Congress on the Archaeology of the Ancient Near East | In English | → Congresses → Archeology |
| ICAD | International Conference on Alzheimer's Disease (and Related Disorders) | In English | → Congresses → Neurology |
| ICAD | Institut des Cadres Dirigeants | In French | → Specialized or (poly)technical colleges → Management |
| ICAD | International Conference on Auditory Display | In English | → Congresses → Human-computer interaction → Telecommunications |
| ICADTS | International Council on Alcohol and Traffic Safety | In French | → Organizations and associations → Medicine → Transport and postal services |
| ICAE | Integrated Computer-Aided Engineering | In English | → Serial publications, periodicals → Computer-based techniques → Engineering, technology |
| ICAITI | Instituto Centroamericano de Investigación y Tecnología | In Spanish | → Research institutes → Research policy → Engineering, technology |
| ICAM | Integrated Computer-Aided Manufacturing | In English | → Computer-based techniques → Engineering, technology |
| ICAMES | Interuniversity Consortium for Arab and Middle Eastern Studies | In English | → Organizations and associations → Area studies |
| ICANAS | International Congress for Asian and Northern African Studies | In English | → Congresses → Area studies |
| ICANN | International Conference on Artificial Neural Networks | In English | → Congresses → Artificial intelligence |
| ICANN | Internet Corporation for Assigned Names and Numbers (www.icann.org) | In English | → Networks, communication |
| ICAO | International Civil Aviation Organization = IOCA | Internacia Organizo pri Civila Aviado | In Esperanto |
In English | → Organizations and associations → Aeronautics, aircraft → Transport and postal services |
| ICAOB | ICAO Bulletin (International Civil Aviation Organization) | In English | → Serial publications, periodicals → Aeronautics, aircraft → Transport and postal services |
| ICAP | International Conference on Atomic Physics | In English | → Congresses → 53198 |
| ICAP | Idaho Child Abuse Prevention (Coalition) (www.idahosheart.org) | In English | → Organizations and associations → Sexual problems → Law, jurisprudence |
| ICARDA | International Center for Agricultural Research in the Dry Areas | In English | → Research institutes → Agricultural sciences |
| ICAS | International Convention of Asia Scholars | In English | → Organizations and associations → Area studies |
| ICB | International Centre of Biocybernetics | In English | → Research institutes → Computer science → Electronics |
| ICC | International Computing Centre (www.unicc.org) = CICE | Centro Internacional de Cálculos Electrónicos | In Spanish = CIC | Centre International de Calcul | In French = CIC | Centro Internacional de Computação | In Portuguese |
In English | → Computer science → United Nations |
| ICC | International Association for Cereal Science and Technology | In English | → Associations → Agricultural sciences |
| ICC | Internet Chess Club | In English | → Organizations and associations |
| ICC | International Chamber of Commerce (www.iccwbo.org) = CCI | Cámara de Comercio Internacional | In Spanish = CCI | Chambre de Commerce Internationale | In French = CCI | Câmara de Comércio Internacional | In Portuguese |
In English | → Organizations and associations → Trade |
| ICC | Interface Control Contractor | In English | → Human-computer interaction |
| ICC | Interface Control Chart | In English | → Human-computer interaction |
| ICC | Intercomputer Communication | In English | → Networks, communication |
| ICC | Intercomputer Channel | In English | → Networks, communication |
| ICCA | International Congress and Convention Association | In English | → Associations → Congresses |
| ICCHP | International Conference on Computers Helping People with Special Needs | In English | → Congresses → Computer-based techniques |
| ICCO | Interkerkelijke organisatie voor ontwikkelingssamenwerking | In Dutch | → Organizations and associations → Development |
| ICCPR | International Conference on Cultural Policy Research | In English | → Civilization, culture, progress → Politics |
| ICCR | Indian Council for Cultural Relations | In English | → Civilization, culture, progress |
| ICD | Interface Control Document | In English | → Human-computer interaction |
| ICD | Interface Control Documentation | In English | → Human-computer interaction |
| ICD | Interface Control Drawing | In English | → Human-computer interaction |
| ICD-O | International Classification of Diseases for Oncology | In English | → Bibliography → Oncology |
| ICDA | Integrated Cached Disk Array | In English | → Hardware |
| ICDAR | International Conference on Document Analysis and Recognition | In English | → Congresses → Document processing |
| ICDS | Interface Control Document Schedule | In English | → Human-computer interaction |
| ICEI | Istituto Cooperazione Economica Internazionale | In Italian | → Organizations and associations → International economic cooperation |
| ICEIS | International Conference on Enterprise Information Systems | In English | → Congresses → Knowledge management → Data |
| ICES | International Council for the Exploration of the Seas (www.ices.inst.dk) | In English | → Organizations and associations → Marine research, oceanography |
| ICES | International Council for Exploration of the Sea | In French | → Organizations and associations → Earth sciences → Zoology |
| ICF | Interface Control Function | In English | → Human-computer interaction |
| ICF | International Canoe Federation (www.canoeicf.com) | In English | → Organizations and associations → Sport, physical exercises |
| ICF | International Coach Federation (www.coachfederation.org) | In English | → Organizations and associations → 659 |
| ICFTU | International Confederation of Free Trade Unions (www.icftu.org) = CISL | Confédération Internationale des Syndicats Libres | In French = CIOSL | Confederación Internacional de Organizaciones Sindicales Libres | In Spanish = CIOSL | Confederação Internacional de Organizações Sindicais Livres | In Portuguese = ICB | International Criminal Bar | In English = BPI | Barreau Pénal International | In French |
In English | → Organizations and associations → Labour, labour economics |
| ICGA | IEEE (Institute of Electrical and Electronics Engineers) Computer Graphics Applications | In English | → Serial publications, periodicals → Graphical processing |
| ICH | Interkultura Centro Herzberg | In Esperanto | → Civilization, culture, progress |
| ICHMT | International Communications in Heat and Mass Transfer | In English | → Serial publications, periodicals → Thermodynamics |
| ICHO | Iran Cultural Heritage Organisation | In English | → Organizations and associations → Civilization, culture, progress |
| ICHR | Indian Council for Historical Research | In English | → Organizations and associations → History |
| ICHRDD | International Centre for Human Rights and Democratic Development (www.ichrdd.ca) = CIDPDD | Centre International des Droits de la Personne et du Développement Démocratique | In French |
In English | → Organizations and associations → Fundamental rights → Democracy |
| ICHRP | International Council on Human Rights Policy | In English | → Organizations and associations → Fundamental rights |
| ICHSEA | International Conference on the History of Science in East Asia | In English | → Congresses → Mathematics and natural sciences → History |
| ICI | Information, Coordination, Incitation | In French | → Computer science |
| ICI | Institutul Naţional de Cercetare-Dezvoltare în Informatică | In Romanian | → Computer science |
| ICID | International Commission for Irrigation and Drainage = CIID | Commission Internationale pour les Irrigations et le Drainage | In French |
In English | → Organizations and associations → 627 → Agricultural sciences |
| ICID | International Commission on Irrigation and Drainage | In English | → Organizations and associations → Agricultural sciences → Environmental technology, water supply, waste management |
| ICIE | Institute for Communications and Information Engineering | In English | → Telecommunications → Computer science |
| ICiSM | IEEE (Institute of Electrical and Electronics Engineers) Circuits Systems Magazine | In English | → Serial publications, periodicals → Electronics |
| ICL | Interface Control Layout | In English | → Human-computer interaction |
| ICLP | Institute of Chinese Literature and Philosophy | In English | → Research institutes → Philosophy, psychology → Literature |