Three-digit codes sent by an HTTP server that indicate
the results of a request for data. Codes beginning with 1 respond to requests
that the client may not have finished sending; with 2, successful requests; with
3, further action that the client must take; with 4, requests that failed
because of client error; and with 5, requests that failed because of server
error.
400, 401, 402, 403, 404, HTTP
400, 401, 402, 403, 404, HTTP