Why.
The Why is the business context: bizStep and disposition from CBV 2.0, and the business transactions the event is tied to.
A raw observation is not yet meaningful; the business step is what makes it shipping, receiving, or commissioning, and the disposition is the object's resulting state. CBV 2.0 defines the controlled vocabulary, and the gateway validates against it rather than accepting free text.
Business transactions bind an event to the documents below. The old tree deep-linked to each of them, so their anchor IDs are preserved here.
bizStepdispositionbizTransactionList
Proof, not adjectives. The gateway's conformance tests pass against GS1's normative artifacts; POST /translate, /validate and /hash answer on this origin. The dated ledger is What ships today.
The documents it ties to.
Each is a business transaction an event references, with the deep-link IDs the old tree carried preserved.
Invoice
An invoice is a business transaction an event can reference through bizTransactionList, tying an observation to the commercial document that settles it. EPCIS 2.0 records the reference; it does not replace the invoice.
Payment
A payment is likewise a referenced business transaction. The event records that the observation relates to it; the settlement itself lives in the financial system, not the event log.
Sales order
A sales order is the transaction a fulfilment event is captured against. The bizStep says what happened; the transaction reference says which order it happened for.
Production order
A production order contextualizes commissioning and manufacturing events. The event attributes the step to the order, so a later trace reads the observation and the order together.
Return merchandise authorization
An RMA is the transaction a return event references. Because storage is append-only, the return is a new event in the object's history, never an edit to the shipment that preceded it.