| Abbreviation | Definition |
|---|---|
| HUP | Harvard University Press |
| HVLA | Hudson Valley Library Association |
| HVSL | Hudson Valley Seed Library |
| HWPL | Hewlett Woodmere Public Library |
| HYL | Harvard Yenching Library |
| i.b.c. | inside back cover |
| I.F.C. | inside front cover |
| IALA | Indiana Academic Library Association |
| IAML | International Association of Music Libraries |
| IBD | Investor's Business Daily |
| IBF | Chicago Municipal Reference Library, Chicago, Illinois |
| IBF | International Book Fair |
| IBFC | International Book Fair Cuba |
| ibid. | same location (ibidem [Lat.]) |
| IBIS | Illinois Bibliographic Information Service |
| IBIS | Integrated Bibliographic Information System |
| IBTD | International Bibliography of Theatre and Dance |
| IC | Index Catalogue |
| ICBC | International Cataloguing and Bibliographic Control |
| ICD | International Classification of Diseases |