RDA Frequently Asked Questions
Table of contents
What is RDA?
What are the strategic aims of RDA?
Which standards is RDA related to?
Who owns RDA?
Who develops and maintains RDA?
How is RDA maintained?
How do I find out about developments in RDA?
Why is there an “official” version and an “original” version of RDA?
What is different between the two versions?
Should I be using the official version of RDA now?
How long will the original version of RDA be available?
What is the Community resources area in RDA Toolkit?
How does RDA support linked data?
What is the RDA Registry?
What is RDA Reference?
What is the "unconstrained" element set?
How are translations of RDA managed?
How are policy statements in RDA managed?
How should RDA data be encoded and displayed?
How is RDA related to MARC 21?
How will RDA work with BIBFRAME?
How do I ask a question or raise an issue about RDA?
How can I get training in RDA?
Why is there a subscription fee to access RDA Toolkit?
What is RDA?
RDA: Resource Description & Access is a package of data elements, guidelines, and instructions for creating library and cultural heritage resource metadata that are well-formed according to international models for user-focused linked data applications.
RDA is published online in the RDA Toolkit. RDA Toolkit is an integrated, browser-based, online product that allows users to interact with a collection of cataloging-related documents and resources, including RDA.
The official version of the RDA standard is published at access.rdatoolkit.org. The original version of the standard (2010-2017) is published at original.rdatoolkit.org. Both versions are accessed through a Toolkit subscription. Free trial subscriptions remain on offer.
What are the strategic aims of RDA?
RDA is being developed to meet the needs of:
- International communities
- Cultural heritage communities
- Linked data communities
Metadata created according to RDA guidelines are intended to support the discovery and identification of resources in library and other cultural heritage collections.
Which standards is RDA related to?
RDA is based on the IFLA Library Reference Model (LRM). When first published, RDA was based on the precursors to the LRM: FRBR, FRAD, and FRSAD.
RDA also uses linked data principles based on Resource Description Framework (RDF) and the Dublin Core Abstract Model (DCAM), following the Data Model Meeting at the British Library in 2007.
The RDA Steering Committee (RSC) has communication protocols and liaisons with other library standards organizations, such as the IFLA Bibliographic Conceptual Models Review Group, IFLA ISBD Review Group and the Library of Congress Network Development and MARC Standards Office, so that decisions can be communicated and documents shared.
Who owns RDA?
RDA is owned by the Copyright Holders of RDA:
- American Library Association (ALA)
- Canadian Federation of Library Associations (CFLA)
- Chartered Institute of Library and Information Professionals (CILIP)
The American Library Association publishes RDA on behalf of the Copyright Holders.
Who develops and maintains RDA?
The RDA Steering Committee (RSC) is responsible for the development and content of the RDA standard on behalf of the RDA Board. Revisions, consolidations, additions, and other changes may be made to RDA only with RSC approval.
The RSC and RDA Board have international representation supported by specialists as required.
The Chair of the RSC is a member of the RDA Board, and the Chair of the RDA Board is a member of the RSC.
How is RDA maintained?
Recommendations for changes to RDA may originate from:
- RSC members
- RDA regional representative bodies, via their regional representative
- RDA users
- via their regional representative body, and if approved, by their regional representative
- via the Wider Community Engagement Officer, if they are not represented by a regional representative body
- RSC task and finish working groups, via the RSC Chair
- RSC/Operations/4 -- Policies and Procedures for Updating RDA Content
- RSC/Operations/5 -- Guidelines for Discussion Papers, Proposals, and Responses to Them
- Full translation, comprising the instructions (published in the RDA Toolkit) and RDA Reference data (published both in the RDA Toolkit and in the RDA Registry)
- Partial translation, comprising only RDA Reference data (published only in the RDA Registry).
- Arabic
- Catalan
- Finnish
- French
- Hungarian
- Italian
- Norwegian
- Spanish
- Danish
- Dutch
- Estonian
- German
- Greek
- Latvian
- Portuguese
- Slovenian
The RSC considers three different types of recommendations: proposals, discussion papers, and fast track changes. All RSC documents must be submitted in English.
More information on the formal processes for these recommendations is contained in two RSC Operations documents:
How do I find out about developments in RDA?
The RDA standard is regularly updated and revised.
The RDA Steering Committee (RSC) publishes regular announcements about RDA in the News and announcements section of the RSC website.
The RSC publishes formal proposals for the development of RDA and the outcomes of discussion in the Documents section of the RSC website.
ALA Digital Reference publishes regular announcements about RDA Toolkit and RDA in the News & Information section of the RDA Toolkit website.
The Revision History section of the RDA Toolkit provides information on major changes to the standard as well as access to earlier versions of the instructions (2019-present). Revision History has two components: Release Notes and the Instruction Archive. The Toolkit will maintain a unique Revision History section for each language version of RDA.
The RDA Development Team makes posts on technical aspects of the RDA Vocabularies in the RDA Registry blog.
Why is there an “official” version and an “original” version of RDA?
RDA was first published online in the RDA Toolkit in June 2010. This is the “original” version (with content updates through April 2017) and is found at original.rdatoolkit.org.
As technology improved, it became evident that the infrastructure supporting the RDA Toolkit website needed to be re-examined and updated.
The RDA Toolkit Restructure and Redesign (3R) Project took shape in October 2016 to review and implement infrastructure and website functionality upgrades. A FAQ about the 3R Project is available here. At the same time, the RSC made the decision to implement content changes to RDA, primarily to integrate the new IFLA Library Reference Model (LRM) into the standard.
The 3R Project resulted in a beta Toolkit website offered for public comment beginning in June 2018.
The original version of RDA was frozen as of the April 2017 release. Updates to the standard from that date forward were integrated into the beta version.
The beta version became the official version of the RDA standard on December 15, 2020 and is found at access.rdatoolkit.org. This marked the formal conclusion of the 3R Project; a summary of the Project’s accomplishments as of November 2020 is provided in RSC/Papers/2020/1 and the 3R Project Final Report was published in 2021.
What is different between the two versions?
The official version of RDA provides a complete set of entities and elements for creating a metadata description set based on RDA guidance and instructions. It is organized according to 13 entities and their elements based on the IFLA LRM, and includes guidance chapters that provide general information.
The official version of RDA has incorporated the terminology, concepts, and approaches associated with linked data, although it can be used in a number of different implementation scenarios.
Unlike AACR2, or even the original version, RDA is not a cataloging manual, and it is no longer exclusively rooted in Anglo-American traditions. Instead, it is an international standard which provides a higher-level framework for aspects of the bibliographic universe. Flexibility in application and in world-wide implementation were key drivers in its design.
Should I be using the official version of RDA now?
Implementation dates for the official version will differ globally depending on a community’s readiness.
Local cataloging agency/community guidance has always been necessary for cataloging codes, to set forth policies on options, to provide further explanations, to include examples specific to a given community, etc. With the official version, communities now have more opportunities to set their own expectations for how RDA will be used, through the use of application profiles, policy statements, community vocabularies, and other local documentation. These can be as complex or as simple as the communities wish.
Community preparations are actively underway; this includes the creation of application profiles and policy statements as well as training and orientation materials. From From 2019-2022, the MARC/RDA Working Group prepared develop discussion papers and proposals for the MARC Advisory Committee (MAC) to support compatibility with new RDA elements.
Implementation planning and timetables are under the control of the communities.
RSC regional representatives may be able to provide further information about implementation efforts in their communities.
How long will the original version of RDA be available?
The original Toolkit, interactive but with frozen content, will remain available to support communities while they are working to implement the official version.
The original Toolkit will not be available interactively forever. At its meeting in May 2023, the RDA Board decided to begin the countdown clock in May 2026 (specific date still to be determined), with the removal of the original Toolkit taking place a year later - May 2027. Once interactive access is removed, PDF pages will still be available through the Instruction Archive in the official RDA Toolkit. More details about the countdown clock will be shared as the information becomes available.
What is the Community Resources area in RDA Toolkit?
The Community Resources area is under active development by the RSC. It first appeared in the September 2020 release. The structure and content may change in upcoming releases as development continues, and content may vary based on the language version of RDA, since this content is up to communities and is not part of the official RDA.
The initial impetus was the need to remove community-specific instructions from RDA to support internationalization, without losing content that those communities continue to rely on. Examples include capitalization instructions and abbreviations.
Community Resources (found on the Resources tab) differs from the user-contributed Documents area (found on the top, dark blue menu bar). Community Resources content is community-curated and maintained and must be lightly vetted by the RSC for RDA conformance. It is a convenient place for a community to access authorized vocabularies, extensions, and refinements to the RDA ontology. The Documents area allows users (individuals or institutions) to create and post documentation unvetted by the RSC that can be used privately or shared locally or globally.
The RSC continues to discuss the governance, maintenance, and processes for Community Resources content. More information will be forthcoming.
How does RDA support linked data?
The RDA entities, elements, and vocabulary encoding schemes are represented in Resource Description Framework (RDF), the syntax of open linked data and the Semantic Web, in the RDA Registry.
Entity and element data are contained in RDF element sets. Vocabulary data are contained in RDF value vocabularies using Simple Knowledge Organization System (SKOS). The element sets and value vocabularies contain the data for RDA Reference and are collectively known as the RDA Vocabularies.
The RDA Registry also provides a set of elements (unconstrained properties; more information here) that do not specify the RDA entities, for use in linked data applications that do not use the IFLA LRM conceptual model that is the basis of RDA.
What is the RDA Registry?
The RDA Registry contains linked data vocabularies that represent the RDA entities, elements, and controlled terminologies as RDA element sets and RDA value vocabularies in Resource Description Framework (RDF).
The RDA Registry sometimes uses different terminology for RDA concepts because the RDA Registry provides RDA in RDF and is intended for developers who are familiar with this terminology. These are the Registry terms with RDA equivalents.
| RDA Registry | RDA |
| class | entity |
| subclass | entity subtype |
| property | element |
| subproperty | element subtype |
| RDA Reference value vocabulary | RDA Vocabulary Encoding Scheme |
Note that the term value vocabulary is not equivalent to vocabulary encoding scheme. However, as a value vocabulary is essentially type of vocabulary encoding scheme that provides IRIs for concepts in its scheme, every RDA VES is a value vocabulary because every RDA VES has IRIs for its concepts.
What is RDA Reference?
RDA Reference includes the labels, definitions, and scope notes of RDA entities, elements, and vocabulary encoding schemes for controlled data values.
RDA Reference data are continuously maintained and are published through GitHub in coordination with Toolkit releases. For further information, see 'Data flow' in About the RDA Registry and vocabularies.
What is the "unconstrained" element set?
The RDA Registry provides an ‘unconstrained’ set of elements. An unconstrained element has a broader meaning than the associated RDA Toolkit element set. The unconstrained elements do not make a distinction between the resource entities Work, Expression, Manifestation, and Item, or between the agent entities Agent, Collective Agent, Person, Corporate Body, and Family.
The unconstrained elements are intended as a tool to interoperate well-formed RDA metadata description sets with metadata from implementations of data models that differ from the IFLA Library Reference Model. This involves transforming data that is conformant with RDA into data that is not conformant with RDA. The RDA Registry provides a set of machine-actionable mappings to support such transformation. The mappings are one-way, from RDA to non-RDA, and they cannot be used to transform non-RDA metadata statements into RDA. They are intended for developing a facility to export RDA metadata for re-use in a non-RDA application.
The unconstrained element set is not an integral part of RDA, and its use in metadata statements is not conformant with RDA.
How are translations of RDA managed?
Although English is the original language of RDA, the RSC, the RDA Board, and the Copyright Holders have a firm commitment to further internationalization of the standard.
The Copyright Holders are prepared to work with interested parties to make new translations of RDA possible. There are two different approaches to translating RDA:
As of February 2022, full translations of RDA are underway in:
Partial translations are underway in:
Translations of RDA comply with the Translation Policy for RDA and RDA Toolkit.
Inquiries about translating RDA should be directed to James Hennelly, Director, ALA Digital Reference.
How are policy statements in RDA managed?
Policy statements are community-based decisions about RDA options. They are published in the RDA Toolkit and are linked to RDA guidance and instructions through the preview pane.
Most policy statements come from national libraries, professional bodies and/or specialist communities that have a legal obligation to make their policies freely available to the public, and the Toolkit supports that obligation through documents on the separate Policies tab. Policy statements may be made available outside of the Toolkit’s paywall, at the agency’s discretion.
Inquiries about policy statements should be directed to James Hennelly, Director, ALA Digital Reference.
How should RDA data be encoded and displayed?
RDA data should be encoded using any format that preserves the integrity of the RDA entities and elements.
RDA supports various database implementation scenarios. See the specific Guidance chapter in the official Toolkit.
The RDA Registry provides vocabularies for encoding RDA data as linked data for the Semantic Web.
The use of RDA data in specific applications, including displays, is out of scope for RDA. RDA data is intended to meet the needs of a wide range of applications and user communities.
How is RDA related to MARC 21?
The MARC 21 format is in common use for encoding RDA data.
The RDA Steering Committee has a liaison protocol with the Library of Congress Network Development and MARC Standards Office, which maintains the MARC 21 standard.
The RDA Toolkit provides alignments between RDA elements and MARC 21 Authority and Bibliographic encodings which are found in the Element Reference section of each element page.
Full Record Examples of RDA Cataloging include RDA data encoded in MARC 21.
RDA is also encoded in the UNIMARC format, as well as non-MARC formats.
The RSC is planning for a broad mapping solution so that maps between other standards (including encoding standards) and RDA can be easily made and maintained.
How will RDA work with BIBFRAME?
Leaders in these communities began a conversation at the 2019 ALA Annual Conference in Washington, D.C. about the relationship and interoperability between RDA and BIBFRAME.
How do I ask a question or raise an issue about RDA?
There are a number of email discussion lists worldwide where questions about RDA are answered by members of the community. Foremost among them is the unmoderated RDA-L email list, which moved to the ALA Connect site in December 2020. Due to time constraints, the RSC does not provide official responses on any of the lists.
The official communication link with the RSC is through your regional representative or the Wider Community Engagement Officer if you do not have a regional representative.
A feedback form is provided on the RDA Toolkit blog and is also accessible via a menu item in the top right corner of every page in the official Toolkit for comments.
Inquiries about Customer Service and Technical Support for RDA Toolkit, including pricing and subscriptions, renewals, translations, and permissions, should be emailed to rdatoolkit@ala.org.
Inquiries about the RDA Registry and linked data applications should be emailed to the contacts listed on the Registry home page.
How can I get training in RDA?
A free trial of RDA Toolkit is available.
Full record examples of RDA cataloguing are available using pure RDA elements, MARC 21 encoding, and RDA linked data. Other training resources may be found on the Toolkit website.
RIMMF (RDA in Many Metadata Formats) is a freely available tool from The MARC of Quality for creating RDA data that can be exported in various encodings. It can be used for RDA linked data training and small-scale applications.
RDA training is available online in a variety of ways from regional, national, or specialist experts. Basic instruction workshops, updates, and refreshers are held via webinar or in-person from various professional organizations and are often publicized through RDA-L.
The RSC website includes links to presentations on RDA made by members of the RDA Steering Committee. There are also presentations on the RDA YouTube channel.
In addition, there are many printed volumes on various aspects of RDA, including Introducing RDA: A Guide to the Basics after 3R, Second Edition and the forthcoming RDA Essentials, Second Edition. Other titles may be found in the ALA Store.
Why is there a subscription fee to access RDA Toolkit?
The subscription fee covers development and production costs of RDA Toolkit.
The costs of time spent by RDA Board and RDA Steering Committee members are absorbed by their employers and not passed on to subscribers.
The RDA Vocabularies containing RDA Reference data, in the RDA Registry for linked data applications, are freely available under an open license.
For more information on RDA Toolkit, including subscriptions and systems requirements, visit the Toolkit FAQ. For questions not addressed there, email rdatoolkit@ala.org.
Updated 28 November 2022