Narrowest Concern

Kind: principle

Layer: Structural Core

Record: architecture:narrowest-concern

Severity: mandatory

Scope: file

Canonical: Ontology

A design rule that a file is classified under the narrowest declared role that describes it accurately.

Listed in Architecture principles, after One Concern Per File and before Layer Spine Precedence.

Requires

• Classification Judgment

Reinforces

• Placement Predictability

Enables

• Layer Spine Precedence

Conflicts with

• Saturated Role Tag

Contracts

• Concern Classification

Violated by

• Saturated Role Tag

Refactored by

• Reclassify to the Narrower Role

Severity

• mandatory

Category

• Taxonomy / Classification / Naming

Enabled by

• One Concern Per File

Linked from

• The layer spine
• Taxonomy / Classification / Naming
• Taxonomy / Classification / Naming
• Taxonomy
• Severity levels