Delegation chain specifications describe the shape of conveyed authority. They leave the verifier's half of the exchange underdetermined. Two verifiers can check the same chain, both report success, and enforce different policy. This document states what a verifier must do: the explicit inputs evaluation depends on, and four rules that keep evaluation fail-closed. The rules are drawn from the Grant & Autonomy Lifecycle (GAL) and Provenance & Trust Context (PTC) specifications and from a public reference implementation.