WebSocket close codes

Close code (uint16)	Codename	Internal	Customizable	Description
0-999	-	Yes	No	Unused
1000	`CLOSE_NORMAL`	No	No	Successful operation, regular socket shutdown
1001	`CLOSE_GOING_AWAY`	No	No	One of the socket endpoints is exiting
1002	`CLOSE_PROTOCOL_ERROR`	No	No	Error in one of the endpoints while processing a known message type
1003	`CLOSE_UNSUPPORTED`	No	No	Endpoint received unsupported data type (text/binary)
1004	-	Yes	No	Unused
1005	`CLOSED_NO_STATUS`	Yes	No	Expected close status, received none
1006	`CLOSE_ABNORMAL`	Yes	No	No close code frame has been receieved
1007	Unsupported Data	No	No	Endpoint received inconsistent message (e.g. non-UTF8 data within a string)
1008	Policy Violation	No	No	Endpoint policy was violated, is a generic code used when codes 1003 and 1009 aren't suitable
1009	`CLOSE_TOO_LARGE`	No	No	Data frame size is too large
1010	Missing Extension	No	No	Client asked for extension that server didn't reply with
1011	Internal Error	No	No	Internal server error while operating
1012	Service Restart	No	No	Server/service is restarting
1013	Server Overload/Try Again Later	No	No	Try Again Later code; temporary server condition forced to block client's request
1014	-	Yes	No	Unused; reserved for later
1015	TLS Handshake Fail	Yes	No	TLS handshake failure
1016-1999	-	Yes	No	Reserved for later
2000-2999	-	Yes	No	Reserved for websocket extensions
3000-3999	-	Yes	Yes	Reserved for frameworks, can be registered at IANA
4000-4999	-	No	Yes	Available for applications