What is RDA Cataloguing?

RDA — Resource Description and Access — is the international standard for creating library catalogue records. It replaced the older AACR2 standard and is now used by national libraries and cataloguing networks worldwide, including the Library of Congress, the British Library, and the Program for Cooperative Cataloging (PCC).

RDA was designed to work better with modern discovery systems, digital resources, and linked data environments. It describes what resources are, how they were created, and how they relate to each other in a way that machine systems can understand and use consistently.

What RDA changed

RDA introduced a set of MARC fields and conventions that help catalogue systems and discovery layers describe resources more precisely and consistently.

Fields 336, 337, 338 — Content, Media, and Carrier Type

These three fields replaced the General Material Designation (GMD), which was a free-text note in 245 $h such as [electronic resource] or [videorecording]. RDA requires precise, controlled vocabulary terms instead.

These fields are machine-readable and standardised across all libraries, which enables faceted searching by format in Koha and other discovery systems.

Field 264 — Production, Publication, Distribution, Manufacture

RDA replaced the older 260 field with 264. The key difference is that 264 uses a second indicator to distinguish between different types of publication activity — publication (ind2=1), distribution (ind2=2), manufacture (ind2=3), and copyright (ind2=4). This matters for e-resources and complex publishing relationships that AACR2’s single 260 field could not fully represent.

040 $e — Description conventions

Every RDA record has $e rda in field 040 to indicate the cataloguing standard used. Shared cataloguing networks such as OCLC WorldCat and the PCC use this to identify whether a record was created under RDA or an older standard.

End of AACR2 abbreviations

AACR2 used abbreviated Latin terms throughout records — ill. for illustration, p. for pages, [s.l.] for place unknown. RDA uses full words in the language of the cataloguing agency. Records that have not been updated may still contain these abbreviations.

Why update older records?

Most libraries hold a mix of records: some created under AACR2 (before around 2013), some under RDA. There are practical reasons to bring older records up to RDA standards:

• Discovery: Koha and other modern ILS systems use 336/337/338 to power format facets in search. Records without these fields do not appear in format-filtered searches.
• Shared cataloguing: Records submitted to OCLC WorldCat or the PCC must meet RDA requirements to be accepted and reused by other libraries.
• Consistency: A catalogue with mixed AACR2 and RDA records produces inconsistent search results and display anomalies — particularly in faceted search and brief display.

How MARCReady handles RDA conversion

MARCReady’s RDA Helper (under Tools) automates the batch conversion of AACR2-era records to RDA. It analyses each record and applies the following changes:

• Converts field 260 to 264 (publication information), setting ind2=1
• Removes the obsolete General Material Designation $h subfield from 245
• Derives and adds fields 336, 337, and 338 from the record’s Leader byte 06
• Marks the record as catalogued under RDA conventions (040 $e rda)

MARCReady will not overwrite fields that are already correctly coded. You can review all changes record by record before exporting.

For more detail on what MARCReady fixes automatically and what requires librarian review, see What MARCReady Can Fix.

Further reading

• LC RDA Information and Resources — Library of Congress
• RDA Toolkit — the official standard reference (subscription required for full access)
• RDA Official — what is changing — MARCReady’s guide to the post-3R transition