Green Button Alliance Rate Limits

Rate-limit signalling is declared on exactly one Green Button surface - the OpenESPI Authorization Server's OAuth2 client-management API, which returns 429 with three X-RateLimit-* headers. No numeric limit is published anywhere: the header descriptions say "Request limit per hour" and "Remaining requests in current window" without stating the value. The CMD ESPI resource server contract declares no 429 and no rate-limit headers at all, so throttling on a certified Data Custodian is that utility's own policy, not a Green Button contract term.