Overview
SIST ISO 24622-2:2021 - "Language resource management - Component metadata infrastructure (CMDI) - Part 2: Component metadata specification language" defines the XML representations and specification language for Component Metadata (CMD) used to describe language resources and related digital objects. It specifies how CMDI records, reusable CMD components and profiles are represented so that tools, registries and catalogues can interoperate across the metadata lifecycle. The standard complements ISO 24622-1 by constraining and extending the CMD model for practical XML schema generation and use.
Key topics and technical requirements
- XML representations of CMDI instances: formal structure for CMD records including core elements such as ****, ****, and **** to describe resources, proxies, relations and journal files.
- CCSL (CMDI Component Specification Language): a machine-actionable specification language for defining CMD components, elements and attributes; includes header metadata and rules for transforming CCSL into CMD profile schema definitions.
- Components, elements and attributes: rules for grouping reusable metadata elements into components, nesting components, and defining attributes (including cue attributes and value schemes).
- Interoperable schema generation: guidance on converting CCSL definitions into XML schema (CMD profile schema) with clear content models, namespaces and validation expectations.
- Semantic linking: support for concept links and linking components/elements to entries in semantic registries (e.g., CLARIN Concept Registry) and use of persistent identifiers (PID).
- Conformance and lifecycle: practical constraints (e.g., one root component per profile, element-to-component ownership) to ensure consistent interpretation across tools.
Practical applications and who uses this standard
ISO 24622-2 is designed for professionals building, validating and managing metadata for language resources and related digital collections. Typical users include:
- Metadata modellers creating resource-specific profiles from reusable CMD components.
- Repository and catalogue developers implementing CMDI-compliant ingestion, validation and discovery services.
- Digital humanities researchers and language technologists who need rich, interoperable metadata for corpora, lexica, recordings and annotations.
- Infrastructure providers (e.g., CLARIN) maintaining component and concept registries, tools and transformation pipelines.
Practical uses include building interoperable metadata schemas, enabling fine-grained descriptions (collection to item level), supporting metadata reuse, and linking metadata to semantic concept registries for improved discoverability.
Related standards
- ISO 24622-1 (Component metadata model)
- ISO 24619 (persistent identifiers)
- ISO 30042 (data categories)
- IETF BCP 47 / RFC 5646 and RFC 6838 (language tags, media types)
Keywords: ISO 24622-2, CMDI, component metadata, CCSL, XML metadata schema, language resource management, metadata profiles, CLARIN, semantic registry, persistent identifier.