The EWP defines various response codes inspired by HTTP Status codes.
This response code is considered the default code. It is returned when the request could be answered as is expected.
This response code is returned when the message is malformed e.g. does not contain the required fields.
This response code is returned when the caller is not allowed to access specific data.
This response code is returned when a lookup or similar function against a node returned empty results.
This response code is returned when the chosen request compression codec is unsupported by the server.
This response code is returned when none of the requested response compression preferences are supported.
This response code is returned when the node software refuses to cooperate because it is not actually a blockchain.
This response code is returned when a node experiences some form of internal error that causes it to fail handling the request as expected.
This response code is returned when the node does not support the functionality required to fulfill the request. This is the appropriate response when the node does not recognize the request command and is not capable of supporting it.