~ HTTP Status Codes Cats :) ~
Voor Anneke
100 - Continue

This means that the server has received the request headers, and that the client should proceed to send the request body (in the case of a request for which a body needs to be sent; for example, a POST request). If the request body is large, sending it to a server when a request has already been rejected based upon inappropriate headers is inefficient. To have a server check if the request could be accepted based on the request's headers alone, a client must send Expect: 100-continue as a header in its initial request and check if a 100 Continue status code is received in response before continuing (or receive 417 Expectation Failed and not continue).
101 - Switching Protocols

This means the requester has asked the server to switch protocols and the server is acknowledging that it will do so.
200 - OK

Standard response for successful HTTP requests. The actual response will depend on the request method used. In a GET request, the response will contain an entity corresponding to the requested resource. In a POST request the response will contain an entity describing or containing the result of the action.
201 - Created

The request has been fulfilled and resulted in a new resource being created.
202 - Accepted

The request has been accepted for processing, but the processing has not been completed. The request might or might not eventually be acted upon, as it might be disallowed when processing actually takes place.
204 - No Content

The server successfully processed the request, but is not returning any content.
206 - Partial Content

The server is delivering only part of the resource due to a range header sent by the client. The range header is used by tools like wget to enable resuming of interrupted downloads, or split a download into multiple simultaneous streams.
207 - Multi-Status

The message body that follows is an XML message and can contain a number of separate response codes, depending on how many sub-requests were made.
300 - Multiple Choices

Indicates multiple options for the resource that the client may follow. It, for instance, could be used to present different format options for video, list files with different extensions, or word sense disambiguation.
301 - Moved Permanently

This and all future requests should be directed to the given URI.
302 - Found

This is an example of industrial practice contradicting the standard. HTTP/1.0 specification (RFC 1945) required the client to perform a temporary redirect (the original describing phrase was "Moved Temporarily"), but popular browsers implemented 302 with the functionality of a 303 See Other. Therefore, HTTP/1.1 added status codes 303 and 307 to distinguish between the two behaviours. However, some Web applications and frameworks use the 302 status code as if it were the 303.
303 - See Other

Schrödinger's cat
The response to the request can be found under another URI using a GET method. When received in response to a POST (or PUT/DELETE), it should be assumed that the server has received the data and the redirect should be issued with a separate GET message.
304 - Not Modified

Indicates the resource has not been modified since last requested. Typically, the HTTP client provides a header like the If-Modified-Since header to provide a time against which to compare. Using this saves bandwidth and reprocessing on both the server and client, as only the header data must be sent and received in comparison to the entirety of the page being re-processed by the server, then sent again using more bandwidth of the server and client.
305 - Use Proxy

Many HTTP clients (such as Mozilla and Internet Explorer) do not correctly handle responses with this status code, primarily for security reasons.
307 - Temporary Redirect

In this occasion, the request should be repeated with another URI, but future requests can still use the original URI. In contrast to 303, the request method should not be changed when reissuing the original request. For instance, a POST request must be repeated using another POST request.
400 - Bad Request

The request cannot be fulfilled due to bad syntax.
401 - Unauthorized

Similar to 403 Forbidden, but specifically for use when authentication is possible but has failed or not yet been provided. The response must include a WWW-Authenticate header field containing a challenge applicable to the requested resource. See Basic access authentication and Digest access authentication.
402 - Payment Required

Reserved for future use. The original intention was that this code might be used as part of some form of digital cash or micropayment scheme, but that has not happened, and this code is not usually used. As an example of its use, however, Apple's MobileMe service generates a 402 error ("httpStatusCode:402" in the Mac OS X Console log) if the MobileMe account is delinquent. In addition, YouTube uses this status if a particular IP address has made excessive requests, and requires the person to enter a CAPTCHA.
403 - Forbidden

The request was a valid request, but the server is refusing to respond to it. Unlike a 401 Unauthorized response, authenticating will make no difference. On servers where authentication is required, this commonly means that the provided credentials were successfully authenticated but that the credentials still do not grant the client permission to access the resource (e.g. a recognized user attempting to access restricted content).
404 - Not Found

The requested resource could not be found but may be available again in the future. Subsequent requests by the client are permissible.
405 - Method Not Allowed

A request was made of a resource using a request method not supported by that resource; for example, using GET on a form which requires data to be presented via POST, or using PUT on a read-only resource.
406 - Not Acceptable

The requested resource is only capable of generating content not acceptable according to the Accept headers sent in the request.
408 - Request Timeout

The server timed out waiting for the request. According to W3 HTTP specifications: "The client did not produce a request within the time that the server was prepared to wait. The client MAY repeat the request without modifications at any later time."
409 - Conflict

Indicates that the request could not be processed because of conflict in the request, such as an edit conflict.
410 - Gone

Indicates that the resource requested is no longer available and will not be available again. This should be used when a resource has been intentionally removed and the resource should be purged. Upon receiving a 410 status code, the client should not request the resource again in the future. Clients such as search engines should remove the resource from their indices. Most use cases do not require clients and search engines to purge the resource, and a "404 Not Found" may be used instead.
411 - Length Required

The request did not specify the length of its content, which is required by the requested resource.
413 - Request Entity Too Large

The request is larger than the server is willing or able to process.
414 - Request-URI Too Long

The URI provided was too long for the server to process.
416 - Requested Range Not Satisfiable

The client has asked for a portion of the file, but the server cannot supply that portion. For example, if the client asked for a part of the file that lies beyond the end of the file.
417 - Expectation Failed

The server cannot meet the requirements of the Expect request-header field.
418 - I'm a teapot

This code was defined in 1998 as one of the traditional IETF April Fools' jokes, in RFC 2324, Hyper Text Coffee Pot Control Protocol, and is not expected to be implemented by actual HTTP servers. However, known implementations do exist. This error is given when trying to brew coffee in a tea pot.
422 - Unprocessable Entity

The request was well-formed but was unable to be followed due to semantic errors.
423 - Locked

The resource that is being accessed is locked.
424 - Failed Dependency

The request failed due to failure of a previous request (e.g. a PROPPATCH).
425 - Unordered Collection

Defined in drafts of "WebDAV Advanced Collections Protocol", but not present in "Web Distributed Authoring and Versioning (WebDAV) Ordered Collections Protocol".
426 - Upgrade Required

The client should switch to a different protocol such as TLS/1.0.
429 - Too Many Requests

The user has sent too many requests in a given amount of time. Intended for use with rate limiting schemes. Proposed in an Internet-Draft.
431 - Request Header Fields Too Large

The server is unwilling to process the request because either an individual header field, or all the header fields collectively, are too large. Proposed in an Internet-Draft.
444 - No Response

An nginx HTTP server extension. The server returns no information to the client and closes the connection (useful as a deterrent for malware).
450 - Blocked by Windows Parental Controls

A Microsoft extension. This error is given when Windows Parental Controls are turned on and are blocking access to the given webpage.
500 - Internal Server Error

A generic error message, given when no more specific message is suitable.
502 - Bad Gateway

The server was acting as a gateway or proxy and received an invalid response from the upstream server.
503 - Service Unavailable

The server is currently unavailable (because it is overloaded or down for maintenance). Generally, this is a temporary state.
506 - Variant Also Negotiates

Transparent content negotiation for the request results in a circular reference.
508 - Loop Detected

The server detected an infinite loop while processing the request (sent in lieu of 208).
509 - Bandwidth Limit Exceeded

This status code, while used by many servers, is not specified in any RFCs.
599 - Network connect timeout error

This status code is not specified in any RFCs, but is used by some HTTP proxies to signal a network connect timeout behind the proxy to a client in front of the proxy.