B.3.4:4.2 - Give dates their actual meaning

A valid_until: ISO-8601-date | null field is used only when the receiving claim or applicable rule has a calendar boundary to convey. State what the date bounds. A review-due date requests reconsideration; a qualification, right or resource-use end date can terminate an allowed use. Do not merge these meanings into a global expiry of the carrier.

An absent or null date means that this field supplies no calendar boundary. It asserts neither perpetual validity nor invalidity and creates no mandatory justification for a missing date. Applicable event or condition limits still govern the use.

Where a required review period applies, follow it until it is changed by someone with the necessary authority. Evaluate its protective purpose, threshold basis and displaced cost separately when deciding whether to propose that change. Questioning the policy is not permission to ignore it.