ISO/IEC 21000-3:2003

Overview

ISO/IEC 21000-3:2003 - Digital Item Identification (DII) is Part 3 of the MPEG‑21 multimedia framework. It specifies how to uniquely identify Digital Items (the structured multimedia objects defined in ISO/IEC 21000-2) and their parts, how to reference intellectual property related to those items, and how to identify applicable description schemes. The standard defines a simple, flexible identification model that integrates with the Digital Item Declaration (DID) and avoids replacing existing identification systems already in use.

Key topics and technical requirements

• Unique identifiers for Digital Items and parts: mechanisms to assign identifiers to items, containers, components and fragments.
• Identification of IP and abstractions: ability to identify intellectual property or abstract representations related to Digital Items.
• Description scheme identification: linking Digital Items to metadata and descriptive schemes via identifiers.
• XML Schema: the DII defines an XML Schema for embedding identifiers in Digital Item Declarations (Clause 4 and 4.4).
• Identifier elements: structured elements such as Identifier, RelatedIdentifier, and Type with defined syntax and semantics.
• Integration point with DID: identifiers are placed in the DID STATEMENT element to associate them with a Digital Item or its components.
• Registration authority role: Annex A specifies requirements for registration authorities that manage identification systems for use in MPEG‑21 (application procedure, responsibilities, appeal).
• Resolution and interoperability: Annex B discusses resolution-system considerations for resolving identifiers to metadata and related resources.
• Reference list of schemes: Annex C catalogs existing identification and description schemes (examples include DOI, ISBN, ISRC, ISAN, ISSN, ISWC, GRID, ONIX, Dublin Core).

Applications and practical value

• Digital media distribution: uniquely identify albums, tracks, images, and associated assets for delivery and cataloging.
• Rights management and DRM: link Digital Items to rights expressions, provenance and IP metadata.
• Content aggregation and syndication: enable interoperable cross-platform referencing of multimedia assets.
• Libraries and archives: persistent identification for preservation, citation and discovery.
• Metadata systems and registries: map existing identifiers (DOI, ISBN, ISRC, etc.) into MPEG‑21 Digital Items without replacing established schemes.

Who should use this standard

• Multimedia platform developers and system architects
• DRM, rights-management and metadata engineers
• Content publishers, distributors and aggregators
• Libraries, archives and digital preservation specialists
• Standards implementers integrating MPEG‑21 DID and identifier resolution

Related standards

• ISO/IEC 21000 (MPEG‑21) family: Part 1 (Vision), Part 2 (Digital Item Declaration), Part 4 (IPMP), Part 5 (Rights Expression Language), Part 9 (File Format)
• Common identification schemes referenced in Annex C: DOI, ISBN, ISRC, ISAN, ISSN, ISWC, GRID, ONIX, Dublin Core, and URL-based schemes.

Keywords: ISO/IEC 21000-3, MPEG-21, Digital Item Identification, DII, Digital Item, Digital Item Declaration, identifier, metadata, registration authority, identifier resolution.