# Invariant Tag

> A formal definition of the tag for a file that states a property the domain must keep true across every change, filed in an invariants folder.

Record: `lexicon:invariant-tag`
Kind: artifact
Layer: [Structural Core](https://banes-lab.com/records/layer/structural-core.md)
Canonical: https://banes-lab.com/ontology/lexicon#lexicon-invariant-tag

Listed in [Lexicon terms](https://banes-lab.com/api/records/lexicon.md), after [Aggregate Tag](https://banes-lab.com/records/lexicon/aggregate-tag.md) and before [Rule Tag](https://banes-lab.com/records/lexicon/rule-tag.md).

## Category

- [Domain Concerns](https://banes-lab.com/records/lexicon-category/domain-concerns.md)