Skip to content

TDM Service Metadata

Machine-readable TDM rights signals conformant with W3C TDMRep, providing content-addressed delivery of tdm-reservation and tdm-policy properties via ISCC. Designed for content identification and discovery where identity, provenance, and trust context complement the reservation signal.

JSON Schema: tdm.json

Example

{
  "@context": "http://purl.org/iscc/context/0.8.0.jsonld",
  "@type": "TDM",
  "$schema": "http://purl.org/iscc/schema/tdm-0.8.0.json",
  "iscc": "ISCC:MAACAJINXFXA2SQX",
  "tdm_reservation": 1,
  "tdm_policy": "https://example.com/tdmrep-policy.json"
}

Overview

Under EU copyright law (DSM Directive, Article 4), text and data mining of lawfully accessed content is permitted by default - including for commercial AI training. Rightsholders who do not expressly reserve their rights in a machine-readable manner have no legal basis to prevent such use. The AI Act, Article 53 reinforces this by requiring GPAI providers to identify and comply with TDM reservations.

The W3C TDMRep protocol defines two properties for this purpose - tdm-reservation (integer 0/1) and tdm-policy (URL) - deliverable via well-known files, HTTP headers, HTML meta tags, EPUB metadata, and PDF XMP.

This schema carries the same TDMRep signals through a sixth channel: content-addressed lookup using ISCC (ISO 24138:2024). A consumer can compute an ISCC fingerprint from any file and query an ISCC registry for its TDM status - even when the file has been redistributed, reformatted, or stripped of embedded metadata.

W3C TDMRep Conformance

The schema fields map directly to the W3C TDMRep namespace (http://www.w3.org/ns/tdmrep#):

ISCC field TDMRep property Namespace IRI
tdm_reservation tdm-reservation http://www.w3.org/ns/tdmrep#reservation
tdm_policy tdm-policy http://www.w3.org/ns/tdmrep#policy

JSON-LD expansion of an ISCC TDM declaration produces the same RDF predicates as TDMRep signals embedded in EPUB or PDF content. The tdm_policy field links to standard TDMRep ODRL policy documents - existing publisher policies work without modification.

Embedded and Standalone Forms

TDM signals appear in two forms within the ISCC ecosystem:

  • Standalone (@type: TDM) - Served by ISCC registries as independent JSON-LD documents, bound to content via the iscc field which becomes the RDF subject (@id)
  • Embedded - Nested inside ISCC Metadata declarations under a tdm wrapper key, using JSON-LD @nest semantics (nested properties promote to the parent subject - no intermediate blank node)

Both forms share one JSON-LD context and expand to identical RDF triples on the two TDMRep predicates.

Field Reference

@context

Name Type Default Definition
@context string-uri http://purl.org/iscc/context The JSON-LD Context URI for ISCC metadata.

@type

Name Type Default Definition
@type string TDM The type of service metadata.

$schema

Name Type Default Definition
$schema string-uri http://purl.org/iscc/schema/tdm-0.8.0.json The JSON Schema URI for TDM service metadata.

iscc

Name Type Default Definition
iscc string none An ISCC-CODE or ISCC-ID identifying the digital content this TDM declaration applies to. Mapped to JSON-LD @id, making it the RDF subject of the declaration.

Example: ISCC:MAACAJINXFXA2SQX

tdm_reservation

http://www.w3.org/ns/tdmrep#reservation Status: stable

Name Type Default Definition
tdm_reservation integer none Blanket TDM reservation flag, semantically equivalent to W3C TDMRep tdm-reservation. 1 = rights reserved (EU DSM Art. 4 opt-out), 0 = not reserved, absent = undeclared.

Example: 1

tdm_policy

http://www.w3.org/ns/tdmrep#policy

Name Type Default Definition
tdm_policy string-uri none URL of a TDM Policy document (typically a JSON-LD ODRL Offer profiling TDMRep). Semantically equivalent to W3C TDMRep tdm-policy.

Example: https://example.com/tdmrep-policy.json