Governance and Versioning

Governance & Versioning

SIGNET is stewarded by Concert Foundation as a neutral, open standard. This page covers how the standard is versioned, what counts as normative, and how changes are controlled.

Stewardship

• The standard is stewarded by Concert Foundation.
• The artifacts are dedicated to the public domain under CC0 1.0 — the vocabulary is meant to be implemented everywhere, by anyone, without friction or attribution burden.
• Concert holds no proprietary claim over the model; it stewards its evolution through the Standards Committee and the formal change-control process.
• No contributor, and no commercial operator (including Score Networks), gains a preferential position.

Normative vs non-normative

The single most important governance distinction:

Tier	What	How it changes
Normative	schema/, closed codelists, and conformance/levels.md + the conformance suite/ + report-schema.json	Only through the Standards Committee revision process, with a published comment period.
Non-normative	docs/, examples/, open codelist values, mapping notes, the conformance adapter/ reference code, this wiki	May be updated freely by pull request.

The schema takes precedence over the prose if they ever conflict. See Validation & Conformance → Precedence.

Semantic versioning

The CDM uses Semantic Versioning:

• MAJOR changes only on a breaking change to the core model.
• MINOR versions add backward-compatible structure.
• PATCH versions clarify without changing meaning.

Every published version is permanently retrievable at a version-stable URI under concert.foundation/signet/<version>/. Implementations declare the CDM version they target.

The conformance suite is versioned with the CDM: a certification is always qualified by both versions (e.g. "SIGNET Full — CDM v0.1, suite v0.1"). A new CDM major version requires re-certification; minor/patch suite updates that only add or clarify tests do not invalidate existing certifications but may apply at renewal. See Conformance Harness.

Release history

From CHANGELOG.md:

Version	Highlights
0.5.0 (2026-06)	Agent demonstration (agent/): a runnable proof that a synthetic agent takes a governed, accountable, conformant action — reads a SourcingEvent, is bounded by a Mandate (its €12M value exceeds the €10M autonomous ceiling, so human approval is required), applies the published MAT evaluation Policy, and emits an Award Decision with rationale, inputs, policies applied, human approval, and provenance, plus a five-event hash-chained trail; the runner verifies the output is conformance-clean (every object validates, the chain holds, tampering is detected); CI runs the demo on every commit.
0.4.0 (2026-06)	Conformance harness (conformance/): Core/Full levels, the public suite, a reference adapter (reaches Full) and a broken adapter (rejected), neutrality rules CN-1…CN-4; signet-to-ubl.js refactored to a pure toUBL(); CI runs the harness on every commit.
0.3.0 (2026-06)	Runnable signet-to-ubl.js transform → Peppol BIS Billing 3.0; verify-ubl.py reconciliation; CI now proves convertibility on every push; committed invoice.ubl.xml.
0.2.0 (2026-06)	Complete OCDS-aligned process layer (Need, Evaluation, Award, Contract, Order, Catalogue, Obligation, Invoice); EN 16931 building blocks (Unit, InvoiceLine, VatBreakdown); EN 16931-mapped Invoice (33 BTs/BGs); Draft-07 allOf fix preserving BT annotations on $ref.
0.1.0 (2026-06)	Foundation layer; initial process layer (SourcingEvent, Submission, Policy); agent layer (SyntheticAgent, Mandate, Decision); trust layer (Event, Consent); JSON-LD context; codelists; CI-validated examples.

The specification itself is at v0.1 (Working Draft / Request for Comments) — field- level definitions are illustrative of the model's shape and not yet frozen.

Change control

As a normative artifact, the core model changes only through the formal revision process governed by the Standards Committee, with a published comment period. Non-normative material may be updated freely (specification §12.2).

To propose a change, see Contributing. For adding (rather than changing) structure, see Extensions.

Marks

"SIGNET", "Concert", and "SIGNET Certified" are marks administered by Concert Foundation under the IP & Licensing Policy. The CC0 dedication covers copyright in the artifacts only; it grants no rights in the marks.

Where to go next

• Contributing — the CLA and the change process.
• Extensions — adding structure without forking.
• Validation & Conformance — what conformance and the "SIGNET Certified" mark mean.