If the IMHM were to describe its manuscripts in this manner the project would take decades to complete and, in the meantime, the great majority of the Institute's holdings would remain uncatalogued. For this reason, the policy of the IMHM during its first years was to prepare brief preliminary descriptions on catalogue cards and thus ensure that the great majority of its manuscript records would be retrievable for research. During these first years when thousands of films arrived annually, the most efficient method of supplying descriptions for each manuscript was to copy information from printed catalogues onto file cards. Only those manuscripts that had never been described previously were studied and cataloged from the microfilms. Since 1963, when the Institute moved to the JNUL, almost all the descriptions are based on actual examination of the filmed (or now: digitized) manuscripts and not on printed catalogues alone. Obviously, all physical manuscripts acquired by the NLI Manuscripts Department are catalogued based on examination of the manuscript itself.
The catalogue cards prepared until 1965 were very brief. They included only the author, title, subject, date, library, manuscript shelf mark and microfilm numbers. In 1965 the method of cataloging was revised. More information was added to the cards, such as: folio numbers, type of script, colophons, owner's entries and bibliographical notes. Cards were for the most part no longer reproduced manually by typewriter but by reprographic methods. This form of cataloging continued for twenty years until, in 1986, a version of the ALEPH computer cataloging program developed at the Hebrew University for use in the JNUL was adapted to meet the needs of the IMHM and the Manuscript Department.
Since the end of 1986 the card-catalogues have been closed and all cataloging has been done by computer using the ALEPH system. The entire card catalogue has been transcribed to the computerized catalogue. The online catalogue was updated from the ALEPH 300 system to the web-friendly ALEPH 500 in 2005. The catalogue of manuscripts in NLI's own collection was incorporated into the online catalogue system in May 2006. As of January 2015, there are over 160,000 catalogue records, representing about 150,000 titles of known Hebrew and other manuscripts scattered throughout the world.
The expert staff of the IMHM will be pleased to assist readers in using the catalogues or locating manuscript material.