Agency
Agency answers whether an entity can perform an action
Specification-sourced: quoted from the governing specification, pending the applicable specification-owner approvals. The specification controls.
In plain words
Not every Subject can act: Persons, Organizations, DigitalAgents and established Formations may have agency, while soil, a watershed or a batch of grain participate without it. Agency derives from the semantics of kinds and roles rather than from a universal property.
What it is not
Agency ≠ Authority
Agency is whether an entity can perform an action; Authority is whether it may perform that action in the relevant context. Authority Is Not Agency · Concept Paper (source: 01 §8.3)