Optionaloptions: ErrorOptionsReadonlyreasonAn optional machine-readable reason, rendered into the response body alongside the message. DECLARED HERE rather than sniffed structurally at the mapper so the channel is part of the contract a subclass opts into, and so the mapper needs no import of any subclass to render it (see the header for why that import must not exist).
ReadonlystatusThe response status. 4xx/5xx only — see doErrorResponse.
A reservation exists but cannot be understood, or the table could not be read. 503 and never "no reservation": the absent answer is the one that starts a run, so an unreadable store degrades CLOSED exactly as an unreadable fence does.