| GRISELI | Dispositif National d'Accès à la Littérature Grise | In French | → Knowledge management |
| HAG | Historical Archives of Goa | In English | → History |
| HAL | Hyper Article en Ligne | In French | |
| HELM | Hypertextual Electronic Library of Mathematics | In English | → Data → Mathematics |
| HIR | Hologram Image Register | In English | → Optics |
| IALL | International Association of Law Libraries (www.iall.org) | In English | → Associations → Law, jurisprudence |
| IAUNRC | Inner Asian and Uralic National Resource Center | In English | → Area studies |
| IBC | Indian Books Centre | In English | |
| ICRA | Association de Classification du Contenu de l'Internet | In French | → Internet → Associations |
| ICSTI | International Council for Scientific and Technical Information | In English | → Mathematics and natural sciences → Engineering, technology |
| IDEM | Informations- und Dokumentationsstelle Ethik in der Medizin | In German | → Ethics → Medicine |
| IDEMM | Ingénierie Documentaire, Édition et Médiation Multimédia | In French | → Document processing → Graphic industries, printing, publishing |
| IDIST | Formation et Recherche en Sciences de l'Information et du Document | In French | → Document processing → Knowledge management |
| IDP | International Dunhuang Project | In English | → Manuscripts |
| IDW | Informationsdienst Wissenschaft | In German | → Mathematics and natural sciences |
| IETDL | IET (Institution of Engineering and Technology) Digital Library | In English | → Engineering, technology |
| IFLA | International Federation of Library Associations | In English | → Organizations and associations |
| IFLA | International Federation of Library Associations and Institutions (www.ifla.org) | In English | → Organizations and associations |
| IGB | Inspection Générale des Bibliothèques | In French | → Public administration, government |
| IJSM | Irian Jaya Source Materials | In English | |
| ILS | Integrated Library System = SIGB | Système Intégré de Gestion de Bibliothèque | In French = АБИС | Автоматизированные библиотечные информационные системы | In Russian |
In English | → Knowledge management → Software |
| IMDb | Internet Movie Database | In English | → Cinema, movies |
| INDOC | Indonesisch Documentatie en Informatie Centrum | In Dutch | → Area studies |
| INIST | Institut National d'Information Scientifique et Technique | In French | → Mathematics and natural sciences → Applied sciences, technology |
| INPADOCDB | International Patent Documentation Data Base | In English | → Industrial property |
| IOAOB | Instituut voor de Organisatie van de Administraties der Openbare Besturen | In Dutch | → Research institutes |
| iPAC | Internet/Intranet Public Access Catalogue | In English | → Bibliography → Networks, communication |
| IPIG | ILL Protocol Implementers Group | In English | → Organizations and associations → Networks, communication |
| IR | Information Retrieval | In English | |
| IRAN | Iranian Resources for Academic Needs | In English | |
| IRANDOC | Iranian Information & Documentation Center | In English | |
| ISBN | International Standard Book Number | In English | → Standardization |
| ISD | Internacia Sciencista Dokumentaro | In Esperanto | → Mathematics and natural sciences |
| ISDN | Institut des Sciences du Document Numérique (http://isdn.enssib.fr) | In English | → Document processing |
| ISSN | International Standard Serial Number | In English | → Standardization → Bibliography |
| ITIL | IT Infrastructure Library | In English | → Computer science → Telecommunications |
| JDC | Japan Documentation Center | In English | → Area studies |
| JIAP | Japan Information Access Project | In English | |
| JISC | Joint Information Systems Committee | In English | → Organizations and associations |
| JNUL | Jewish National and University Library | In English | → Judaism → Higher education, universities |
| JPGS | Japan Publications Guide Service | In English | |
| KOHD | Katalogisierung der Orientalischen Handschriften in Deutschland | In German | → Language, linguistics, literature |
| LADL | Laboratoire d'Automatisme Documentaire et Linguistique | In French | → Research institutes → Computer science → Linguistics |
| LAF | Library Application Framework | In English | → 04 |
| LAP | Libraries of Asia Pacific | In English | |
| LCCN | Library of Congress Control Number | In English | → Parliaments, representation |
| LIBER | Ligue des Bibliothèques Européennes de Recherche | In French | → Organizations and associations → Research policy |
| LII | Librarians' Internet Index | In English | → Networks, communication |
| LIMBER | Language Independent Metadata Browsing of European Resources | In English | → Computer science |
| LINC | Library Information Network Consortium | In English | → Organizations and associations |
| LLC | Library of Congress Classification | In English | → Parliaments, representation |
| LNCC | Lecture Notes in Computer Science | In English | → Computer science |
| LTWA | Library of Tibetan Works & Archives | In English | |
| MAI | Machine-Aided Indexing | In English | → Knowledge management |
| MARC | Machine Readible Cataloging | In English | |
| MARLC | Melbourne Asian Research Libraries Consortium | In English | → Area studies |
| MBS | Miniature Book Society | In English | → Organizations and associations |
| MCLC | Modern Chinese Literature and Culture Resource Center | In English | → Civilization, culture, progress → Literature |
| MDL | Master Data Library | In English | → Data |
| MENIC | Middle East Network Information Centre | In English | |
| MERIP | Middle East Research and Information Project | In English | → Research policy |
| MeSH | Medical Subject Headings | In English | → Bibliography → Medicine |
| MHLA | Maritimes Health Libraries Association = ABSM | Association des Bibliothèques de la Santé des Maritimes | In French |
In English | → Associations → Medicine → 6295 |
| MIPP | Microfilming of Indian Publications Project | In English | |
| MOF | Meta-Object Facility | In English | |
| NAL | National Agricultural Library (www.nal.usda.gov) | In English | → Agricultural sciences |
| NARS | National Archives and Record Services | In English | |
| NCC | North American Coordinating Council on Japanese Library Resources | In English | |
| NCECHO | North Carolina Exploring Cultural Heritage Online | In English | → Civilization, culture, progress |
| NCIP-IG | NISO Circulation Interchange Protocol Implementers Group | In English | → Organizations and associations |
| NCOLR | National Council on Orientalist Library Resources | In English | → Organizations and associations → Linguistics |
| NDL | National Diet Library | In English | → Nutrition |
| NISO | National Information Standards Organization | In English | → Organizations and associations → Knowledge management |
| NLDC | National Library and Documentation Centre | In English | |
| NLE | National Library for the Environment | In English | → Nature |
| NMELRC | National Middle East Language Resource Center | In English | → Linguistics |
| NPLG | National Parliamentary Library of Georgia | In English | → Parliaments, representation |
| NUMDAM | NUMérisation de Documents Anciens Mathématiques | In French | → Document processing → Mathematics |
| NZDL | New Zealand Digital Library Project | In English | → Area studies |
| OAIS | Open Archival Information System | In English | |
| OCLC | Online Computer Library Center | In English | → Networks, communication |
| ODDDA | OWTRAD (Old World Traditional Trade Routes) Dromographic Digital Data Archives | In English | → History |
| ÖDOZA | Österreichisches Dokumentationszentrum für Auslandsstudien | In German | → Education |
| OeM | Österreichische Mediathek | In German | |
| OIL | Ontology Inference Layer | In English | → Programming languages |
| OIOC | Oriental and India Office Collections | In English | → Area studies |
| OPAC | Online Public Access Catalog | In English | |
| OPID | Observatório da Profissão de Informação-Documentação | In Portuguese | |
| OSALL | Organisation of South African Law Libraries | In English | → Organizations and associations → Law, jurisprudence |
| PAIR | Portal to Asian Internet Resources | In English | → Networks, communication |
| PAKBO | Pakistan Bibliographical Organization | In English | → Bibliography → Organizations and associations |
| PARADISEC | Pacific And Regional Archive for DIgital Sources in Endangered Cultures | In English | → Language, linguistics, literature → Geography, biography, history |
| PEB | Prêt Entre Bibliothèques | In English | |
| PIALA | Pacific Islands Association of Libraries and Archives | In English | → Associations |
| PIO | Public Information Office | In English | → 659 |
| PLoS | Public Library of Science | In English | → Mathematics and natural sciences |
| PMC | PubMed Central (www.pubmedcentral.nih.gov) | In English | → Biological sciences → Medicine |
| PRDLA | Pacific Rim Digital Library Alliance | In English | → Organizations and associations |
| PSI | Published Subject Indicator | In English | |
| PSWWWVL | Pacific Studies WWW Virtual Library | In English | → Internet → Area studies |
| QES | Qwam E-content Server | In English | → Networks, communication |
| RBMT | Retrospective Bibliographies on Magnetic Tape | In English | |
| RIC | Reta Informado-Centro | In Esperanto | → Networks, communication |
| SAALG | South Asia Archive & Library Group | In English | → Area studies |
| SADOVER | SAmenwerking op het gebied van de DOcumentatie over VERkeerswezen | In Dutch | → Transport and postal services |
| SAMP | South Asia Microform Project | In English | → Area studies |
| SARAI | South Asia Resource Access on the Internet | In English | → Networks, communication → Area studies |
| SARD | South Asia Resources Database | In English | → Area studies |
| SBN | Servizio Bibliotecario Nazionale | In Italian | |
| SBO | Systems Biology Ontology | In English | → Programming languages → Knowledge management → Biological sciences |
| SDBDIS | Sous-Direction des Bibliothèques et De l'Information Scientifique | In French | → Central administration → Mathematics and natural sciences |
| SDI | Selective Dissemination of Information | In English | |
| SEAHTP | South East Asian Historical Texts Project | In English | → Language, linguistics, literature → History |
| SEAiT | Southeast Asian Images and Text | In English | → Area studies |
| SEAM | Southeast Asia Microform Project | In English | → Area studies |
| SEDIC | Sociedad Española de Documentación e Información Científica | In Spanish | → Mathematics and natural sciences |
| SEER | Scholars Engaged in Electronic Resources | In English | |
| SFPL | San Francisco Public Library | In English | |
| SFS | Svensk Författningssamling | In Swedish | |
| SGRL | South Georgia Regional Library (www.sgrl.org) | In English | |
| SIGB | Système Intégré de Gestion de Bibliothèque = ILS, АБИС (look above) |
In French | → Knowledge management → Software |
| SIGLE | System for Information on Grey Literature in Europe | In English | → Knowledge management |
| SORC | Student Organization Resource Center | In English | → Organizations and associations → Education |
| SPL | Science Photo Library | In English | → Mathematics and natural sciences → Photography |
| SRU | Search/Retrieve via URL | In English | |
| SRW | Search/Retrieve Web service | In English | |
| SSEAL | South/Southeast Asia Library | In English | → Area studies |
| SSELP | Sinological Serials in European Libraries Project | In English | → Serial publications, periodicals → Linguistics |
| STEB | Scienca kaj Teknika Esperanto-Biblioteko | In Esperanto | → Mathematics and natural sciences → Applied sciences, technology |
| SUB | Staats- und Universitätsbibliothek | In German | |
| SUDOC | Système Universitaire de Documentation | In French | → Higher education, universities |
| SUSHI | Standardized Usage Statistics Harvesting Initiative | In English | → Computer science |
| TD | Tidskrift för Dokumentation | In Swedish | → Serial publications, periodicals |
| TEL | Thèse en ligne | In French | → Higher education, universities |
| TIB | Technische Informationsbibliothek | In German | → Applied sciences, technology |
| TNA | The National Archives | In English | |
| TOCRoSS | Table of Contents by Really Simple Syndication | In English | |
| UDC | Universal Decimal Classification = UDK | Universala Dekuma Klasifiko | In Esperanto = CDU | Classification Décimale Universelle | In French = UDC | Universele Decimale Classificatie | In Dutch = CDU | Clasificación Decimal Universal | In Spanish = UDC | Universel Decimal Classifikation | In Danish |
In English | |
| UDC | Universele Decimale Classificatie = UDK, CDU (look above) |
In Dutch | |
| UDC | Universel Decimal Classifikation = UDK, CDU (look above) |
In Danish | |
| UDK | Universala Dekuma Klasifiko = UDC, CDU (look above) |
In Esperanto | |
| UDS | Universal Documentation System | In English | → Knowledge management |
| UIUC DLI | University of Illinois at Urbana-Champaign Digital Library Initiative | In English | → Data |
| UKSG | United Kingdom Serials Group | In English | → Organizations and associations → Serial publications, periodicals |
| ULAS | Union List of Astronomy Serials | In English | → Astronomy |
| URI | Uniform Resource Identifier | In English | → Networks, communication |
| USPL | Universal Signal Processing Library | In English | → Telecommunications |
| VEB | Virtuala Esperanto-Biblioteko | In Esperanto | → Internet |
| VMIS | Visual Marine Information Systems | In English | → Marine research, oceanography |
| VMLS | Veterinary Medical Libraries Section | In English | → Veterinary medicine |
| VTL | Virtual Tape Library | In English | → Data |
| VTLS | Visionary Technology in Library Solutions | In English | |
| WAC | WebFeat Administrative Console | In English | → Software |
| WFOL | WonderWeb Foundational Ontologies Library | In English | → Computer science |
| WRD | Water Resource Database | In English | → Hydrology → 627 → Environmental technology, water supply, waste management |
| XBEL | XML Bookmark Exchange Language | In English | → Programming languages → Networks, communication |
| ZIG | Z39.50 Implementers Group | In English | → Organizations and associations |
| ZLB | Zentrale Landesbibliothek | In German | |
| АБИС | Автоматизированные библиотечные информационные системы = ILS, SIGB (look above) |
In Russian | → Knowledge management → Software |