SecRoot.io This document defines the Enforcement-Action HTTP response header field. The field carries an advisory selected-action token from an application to cooperating intermediaries within a trusted boundary. It is advisory and safe to ignore. Recipients apply their local policy in response to the signal. This specification standardizes the field name, syntax, response-path processing model, and safe-to-ignore behavior. It does not standardize the operational meaning, target, duration, or enforcement effect of individual action tokens or parameters, and it does not modify HTTP semantics, TLS, QUIC, or the caching rules of [RFC9111].