ARCS-CUS: Custody Surface

Purpose

ARCS-CUS defines the governance domain applicable to the identification and declaration of record custody. This family establishes requirements for identifying custodians, documenting propagation across vendor and system boundaries, and maintaining visibility into the surfaces through which records are held, processed, retransmitted, or otherwise made materially available. Its purpose is to ensure that custody is declared as an observable governance condition rather than inferred only from architecture diagrams, procurement records, or post hoc investigation.

Governance focus

• Identification of record custodians and materially relevant subprocessors
• Declaration of vendor and system surfaces through which records move
• Distinction between primary custody, delegated custody, and retransmission surface
• Visibility into multi-system propagation and boundary crossing
• Maintenance of custody declarations sufficient for review and audit

Boundary

ARCS-CUS applies wherever custody is distributed, shared, delegated, or extended beyond a single system boundary. It governs the visibility of holding and propagation conditions, whether persistent or transient, where those conditions are relevant to record treatment. This family is concerned with the existence and declaration of custody surface, not merely with contractual relationship or infrastructure ownership. Where records pass through systems that materially affect retention, access, transmission, or exposure, this family applies.

The corresponding control statements for this family are maintained in the Controls catalog.