A downgrade of the account, so it asks for both factors it guards: the password, and a fresh code — a six-digit code from the authenticator app, or a recovery code — which is spent. Without a code the answer is 401 with mfaRequired: true, so a client knows to ask for one. Wrong passwords and wrong codes both count against the step-up lockout. An enrolment never confirmed needs only the password. The owner's databases' policies hear owner.mfa-removed.