How Canonical ESG Evolves

Purpose

This document defines how Canonical ESG evolves over time.

It establishes:

• How changes are proposed
• How architectural components are versioned
• How stability is preserved
• How backward compatibility is assessed
• How regulatory and framework evolution is modelled without semantic drift

Canonical ESG is designed as long-term semantic infrastructure.
Its evolution model prioritises predictability, traceability, and structural integrity.

Architectural Stability Doctrine

Canonical ESG evolution is governed by five stability doctrines:

1. Meaning Before Regulation

Semantic meaning (CDI layer) must remain stable across regulatory cycles.

2. Layer Isolation

Changes in one layer (CERM, CDI, CMP, jurisdiction) do not implicitly modify other layers.

3. Explicit Version Boundaries

All structural changes are versioned. No silent modification is permitted.

4. Immutability of Frozen Artefacts

Once frozen, artefacts are never edited retroactively.

5. Reference Durability

Previously published versions remain referenceable indefinitely.

Architectural Components That May Evolve

Canonical ESG consists of independently versioned components:

• CERM — Canonical ESG Reference Model (data structures)
• CDI — Canonical Disclosure Intents (semantic concepts)
• CMP — Canonical Mapping Packs (framework interpretation)
• Jurisdiction CMPs — Regulatory overlays
• Schemas — Machine-readable specifications
• Documentation — Explanatory materials

Each component evolves independently.

A change to a CMP does not alter CDI meaning.
A jurisdiction update does not redefine semantic concepts.
A schema refinement does not imply reinterpretation.

Versioning Model

Canonical ESG follows a structured semantic versioning approach.

Major Version (X.0.0)

A major version introduces structural architectural change.

Examples:

• Redefinition of a core semantic boundary
• Incompatible restructuring of the data model
• Breaking schema modifications
• Fundamental change in layering logic

Major versions are rare and deliberate.
Prior major versions remain published and referenceable.

Minor Version (X.Y.0)

A minor version introduces additive, backward-compatible evolution.

Examples:

• New CDIs
• New CMPs
• Additional jurisdiction mappings
• Extended examples
• Non-breaking schema enhancements

Minor versions preserve semantic stability.

Patch Version (X.Y.Z)

A patch version corrects errors or clarifies documentation without altering meaning.

Examples:

• Typographical corrections
• Citation fixes
• Clarification of ambiguous explanatory text
• Non-semantic schema corrections

Patch versions never alter disclosure meaning.

Compatibility Classification

Each change is classified into one of the following categories:

• Non-breaking — No impact on prior semantic meaning or structure
• Additive — Expands scope without affecting prior definitions
• Clarificatory — Improves wording without changing meaning
• Breaking — Alters compatibility and requires major version increment

Compatibility classification is documented in changelogs.

Artefact Status Lifecycle

Each published artefact has a defined status.

Draft

• Subject to revision
• Intended for review
• Not recommended for production dependency

Active

• Stable within its version line
• Suitable for implementation
• May receive minor or patch updates

Frozen

• Immutable
• Permanently referenceable
• Will not be modified

Superseded

• Replaced by a newer version
• Retained for historical traceability
• Not updated further

Frozen artefacts are never retroactively edited.

Change Proposal Lifecycle

All structural changes follow a documented lifecycle.

1. Proposal

A written proposal includes:

• Description of the change
• Rationale
• Affected architectural layer(s)
• Compatibility impact
• Migration considerations (if applicable)

2. Architectural Assessment

The proposal is evaluated for:

• Alignment with governance principles
• Semantic stability impact
• Layer isolation compliance
• Compatibility classification
• Risk of regulatory overreach

3. Decision

The maintainer may:

• Accept
• Request revision
• Defer
• Reject with documented reasoning

All decisions are recorded for transparency.

4. Publication

Accepted changes are:

• Assigned a new version number
• Classified by compatibility type
• Documented in the changelog
• Published with explicit status

Backward Compatibility Commitment

Canonical ESG prioritises backward compatibility.

Where compatibility cannot be preserved:

• A new major version is created
• Prior versions remain accessible
• Migration guidance is documented

No published version is invalidated by subsequent evolution.

Users are never forced to upgrade.

Handling External Framework Evolution

External sustainability standards evolve independently.

When frameworks update:

• A new CMP version may be issued
• Prior CMP versions remain frozen
• Framework version numbers are explicitly referenced

Canonical ESG does not retroactively alter prior mappings to reflect new framework interpretations.

Regulatory evolution is modelled — not absorbed into semantic meaning.

Deprecation Policy

Elements may be deprecated but are not removed from frozen versions.

Deprecation:

• Is explicitly documented
• Includes rationale
• Identifies successor elements where applicable

Deprecated elements remain referenceable for historical consistency.

Schema Evolution

Machine-readable schemas evolve under the same versioning discipline.

Schema evolution must:

• Preserve semantic meaning unless part of a major release
• Maintain backward compatibility wherever possible
• Explicitly document structural changes

Schema version numbers correspond to architectural versioning.

Governance Alignment

Evolution decisions operate under the Canonical ESG governance model.

Governance ensures:

• Architectural coherence
• Preservation of neutrality
• Transparent change history
• Non-authoritative positioning

Governance does not assert interpretive authority over external standards.

Summary

Canonical ESG evolves deliberately.

Its evolution model is designed to balance:

• Stability with extensibility
• Neutrality with interpretive clarity
• Backward compatibility with architectural progress

This disciplined evolution framework ensures Canonical ESG can function as durable semantic infrastructure beneath evolving sustainability reporting regimes.