Source Of Record. The authoritative artifact or system allowed to define a specific fact, diagram, decision, term, or generated output contract. A source of record is narrower than the Truth Plane: it names the one maintained home for a particular piece of knowledge so projections, generated artifacts, indexes, and summaries can derive from it without becoming alternate authors.
A decision registry is a source of record for governed decisions: logs, metrics, dashboards, and SIEM exports may explain those decisions, but they do not own them. During recovery, the source of record may provide authoritative intent: the target state actual systems are reconciled toward.