# Canonical Definition

> The requirement that each fact have one authoritative definition that all consumers reference.

Record: `lexicon:canonical-definition`
Kind: constraint
Layer: [Contracts Core](https://banes-lab.com/records/layer/contracts-core.md)
Canonical: https://banes-lab.com/ontology/lexicon#lexicon-canonical-definition

Listed in [Lexicon terms](https://banes-lab.com/api/records/lexicon.md), after [Security Checks](https://banes-lab.com/records/lexicon/security-checks.md) and before [Duplicated Authority](https://banes-lab.com/records/lexicon/duplicated-authority.md).

## Category

- [Schema / Canonical Data / Semantics](https://banes-lab.com/records/lexicon-category/schema-canonical-data-semantics.md)

## Required by

- [Single Source of Truth](https://banes-lab.com/records/architecture/single-source-of-truth.md)

## Linked from

- [Schema / Canonical Data / Semantics](https://banes-lab.com/ontology/principles/architecture-category-schema-canonical-data-semantics.md)
- [Core Vocabulary](https://banes-lab.com/ontology/lexicon/lexicon-category-core-vocabulary.md)