Overview
ISO 20775:2009 - Information and documentation: Schema for holdings information defines a standardized schema to describe holdings for all types of resources (physical and electronic) and formats - printed text, images, sound recordings, video, electronic media, monographs, serials and multipart resources. The standard is designed primarily to appear in query responses and to support the interactive exchange of both stable (e.g., loan policy) and dynamic (e.g., current availability) holdings data. It does not define query protocols or how data is gathered, nor does it provide detailed bibliographic description or serial-claiming procedures.
Key topics and requirements
- Scope of holdings: support for one or more bibliographic resources, identification of copies, sets, pieces and components.
- Availability and access: current availability status, access rights and conditions, and availability policy expressed so a requester can determine whether delivery or access is possible.
- Stable vs dynamic data: accommodation of both persistent metadata (policies, identifiers) and rapidly changing elements (loan status, reservations).
- Optional historical usage: reporting capability for historical usage as a secondary, optional feature.
- Schema artifacts: provides an abstract schema and an XML schema implementation (ISO includes an XML schema annex).
- Modular use: intended to be used as a standalone schema or embedded as a fragment within other bibliographic schemas (for example, as an extension to MODS).
- Simplicity and clarity: derived from earlier holdings schemas (e.g., Z39.50 holdings), but simplified - fewer hierarchical levels, clearer optional/mandatory elements, and element names aligned where possible with ISO 8459.
- Normative references: uses standard codes like ISO 4217 (currency) and adheres to ISO 8459 element conventions.
Applications and who should use it
- Libraries and consortia: local and union catalogues, OPACs, discovery services and interlibrary loan systems that need standardized availability and holdings responses.
- Repository and archive systems: cultural institutions and digital repositories that must communicate holdings, access conditions and delivery options.
- Library system vendors and integrators: implementers of discovery-to-delivery workflows, link resolvers and reservation/fulfillment middleware.
- Search and metasearch services: systems that ingest or reference holdings fragments to present up-to-date availability alongside descriptive metadata.
Practical use cases include responding to availability queries, reporting access policies to authenticated requesters, narrowing search results to immediately available copies, and informing resolution or transfer decisions between systems.
Related standards
- ISO 23950 (OPAC schema) - ISO 20775 acts as a more focused holdings response schema
- ANSI/NISO Z39.50 holdings schema and NCIP (Z39.83) - historical antecedents
- MODS, MARC 21 Holdings - complementary descriptive/harvesting schemas
- Protocols referenced (but not specified by ISO 20775): SRU, Z39.50, OpenSearch, OpenURL
Keywords: ISO 20775:2009, schema for holdings information, holdings schema, library holdings, bibliographic resources, availability, access policy, XML schema, union catalogue.