$process-message response format


On the FHIR site, it says:
The response content type returned is always Bundle with type “message” containing a MessageHeader resource as the first resource, or an HTTP error

But then on the page, it later says:
The server acknowledges the message with a 200 OK with no body

The example on the page aligns with the latter.

Can anyone advise on the standard format for the response? Should it really always be a Bundle with a MessageHeader resource? Also Bundle type “transaction-response” seems more appropriate than “message”.