Business Rules

A business rule is an invariant or a constraint of the domain. It holds whichever use case or interface triggers it. Group the rules in one file per subject, with IDs unique across files.

A business rule is a Derived Document. Change the specifications first, then the rule.

This file is written by repo update; keep notes in another file.

Template

## BR-NNN: Name

| Property      | Value                                                       |
| ------------- | ----------------------------------------------------------- |
| Category      | Invariant, Policy, Calculation, or Authorization            |
| Statement     | One precise sentence                                        |
| Rationale     | Why the rule exists                                         |
| Applies to    | The domain object or use case, by its glossary term         |
| Violated when | The condition that breaks the rule                          |
| Capabilities  | Optional: the capabilities that state the rule              |

| Valid | Invalid |
| ----- | ------- |
| …     | …       |