Policy

A policy is a decision rule that guides or constrains interpretation, authorization, routing, coordination, retention, recovery, or execution.

Policies explain why a command is accepted or rejected, why an observation is disclosed or redacted, why an event is routed to one observer rather than another, why a process retries, compensates, times out, or escalates, or why a boundary exposes one shape instead of another.

A policy is not the same as a policy engine, access-control library, configuration file, retry loop, or validation routine. Those are possible realizations. The semantic policy is the modeled decision rule and the reasons it preserves.

Policies become system graph structure through policy scopes, which attach decision rules to observer models, entity models, process graphs, relation models, projection models, transitions, effects, or boundaries.