Services.
Not every observation is a physical object: a service or a business transaction can be the subject of a transaction event. EPCIS 2.0 models it with the same envelope, and the gateway applies the same laws. The gateway accepts these events under the same laws as any other.
epcListquantityList
A transaction event with no box in it.
"type": "TransactionEvent",
"action": "ADD",
"bizStep": "inspecting",
"bizTransactionList": [
{ "type": "inv",
"bizTransaction": "urn:epc:id:gdti:0950600.01346.INV-3307" }
],
"who": "did:human:qa-inspector", // asserted, graded
"spine:capturedBy": "acct:inspection-firm" // stamped
Illustrative: an inspection service recorded against a transaction. Same envelope, same laws — validated, stamped, graded, hashed, appended.
For the engineer whose events are work, not goods.
The envelope does not care that nothing moved. An inspection, a certification step, a handover of responsibility — each is an observed moment with a business step, an observer and a warrantor, and the same append-only history underneath it.
Proof, not adjectives. The gateway's conformance tests pass against GS1's normative artifacts. See What for the dimension, and What ships today for the dated ledger.