ISO 21127:2023

Overview

ISO 21127:2023 (ISO 21127:2023) defines a reference ontology for the interchange of cultural heritage information. Developed from the CIDOC Conceptual Reference Model (CIDOC CRM), it provides a curated, factual model of the past “at a human scale” and specifies the information needed to exchange and integrate heterogeneous scientific and scholarly documentation and the documented or empirical evidence that supports it. The standard’s goal is semantic interoperability across museums, archives, libraries, and other cultural heritage institutions.

Key topics and technical requirements

• Reference ontology & conceptual model: A formal schema of core classes and properties (the ontology) used to represent cultural heritage information consistently.
• Scope and practical coverage: Covers the union of reference and de facto documentation standards so data encoded in those formats can be expressed in an ISO 21127–compatible form.
• Modeling principles: Guidance on minimality, monotonicity, open-world assumptions, disjointness, and authorship of knowledge bases.
• Applied form and syntax rules: Naming conventions, inheritance, transitivity, logical expressions, property quantifiers, and shortcuts to support machine-processable exchange.
• Spatiotemporal and event modeling: Built-in constructs for events, spatial, temporal and spatiotemporal relations, including fuzzy temporal boundaries.
• Class and property declarations: Comprehensive definitions enabling automatic inference and generation of full property hierarchies.
• Compatibility and extensions: Mechanisms for aligning with geospatial standards (updates in the third edition added properties/subclasses for geospatial alignment) and for extending the model while maintaining interoperability.

Practical applications and users

ISO 21127 is used to achieve semantic interoperability, including:

• Data exchange & integration between museums, archives, libraries and research projects.
• Data migration from legacy systems to modern platforms without loss of meaning.
• Automated transformations and mapping algorithms between heterogeneous metadata schemas.
• Federated and associative queries across integrated cultural heritage resources.
• Conceptual modelling guidance for developers, cataloguers, collection managers, digital humanities researchers, and GIS specialists working with heritage data.

Typical users:

• Museum and archive IT teams, collection managers, metadata specialists, librarians, digital preservation professionals, software developers building aggregation platforms, and researchers in cultural heritage informatics.

Related standards and resources

• CIDOC Conceptual Reference Model (CIDOC CRM) - the originating community model that ISO 21127 formalizes.
• References to geospatial alignment (noted in the third edition) with OCG-related geospatial standards.
• Scope and implementation guidance available on the CIDOC CRM website and the ISO Online Browsing Platform.

Keywords: ISO 21127, CIDOC CRM, cultural heritage information, reference ontology, semantic interoperability, metadata mapping, data integration, heritage collections.