10.2.4 203 Non-Authoritative Information The returned metainformation in the entity-header is not the definitive set as available from the origin server, but is gathered from a local or a third-party copy. The set presented MAY be a subset or superset of the original version. For example, including local annotation information about the resource MAY result in a superset of the metainformation known by the origin server. Use of this response code is not required and is only appropriate when the response would otherwise be 200 (OK). 10.2.5 204 No Content The server has fulfilled the request but there is no new information to send back. If the client is a user agent, it SHOULD NOT change its document view from that which caused the request to be sent. This Fielding, et. al. Standards Track [Page 55] RFC 2068 HTTP/1.1 January 1997 response is primarily intended to allow input for actions to take place without causing a change to the user agent's active document view. The response MAY include new metainformation in the form of entity-headers, which SHOULD apply to the document currently in the user agent's active view. The 204 response MUST NOT include a message-body, and thus is always terminated by the first empty line after the header fields. 10.2.6 205 Reset Content The server has fulfilled the request and the user agent SHOULD reset the document view which caused the request to be sent. This response is primarily intended to allow input for actions to take place via user input, followed by a clearing of the form in which the input is given so that the user can easily initiate another input action. The response MUST NOT include an entity. 10.2.7 206 Partial Content The server has fulfilled the partial GET request for the resource. The request must have included a Range header field (section 14.36) indicating the desired range. The response MUST include either a Content-Range header field (section 14.17) indicating the range included with this response, or a multipart/byteranges Content-Type including Content-Range fields for each part. If multipart/byteranges is not used, the Content-Length header field in the response MUST match the actual number of OCTETs transmitted in the message-body. A cache that does not support the Range and Content-Range headers MUST NOT cache 206 (Partial) responses. 10.3 Redirection 3xx This class of status code indicates that further action needs to be taken by the user agent in order to fulfill the request. The action required MAY be carried out by the user agent without interaction with the user if and only if the method used in the second request is GET or HEAD. A user agent SHOULD NOT automatically redirect a request more than 5 times, since such redirections usually indicate an infinite loop. Fielding, et. al. Standards Track [Page 56] RFC 2068 HTTP/1.1 January 1997 10.3.1 300 Multiple Choices The requested resource corresponds to any one of a set of representations, each with its own specific location, and agent- driven negotiation information (section 12) is being provided so that the user (or user agent) can select a preferred representation and redirect its request to that location. Unless it was a HEAD request, the response SHOULD include an entity containing a list of resource characteristics and location(s) from which the user or user agent can choose the one most appropriate. The entity format is specified by the media type given in the Content- Type header field. Depending upon the format and the capabilities of the user agent, selection of the most appropriate choice may be performed automatically. However, this specification does not define any standard for such automatic selection. If the server has a preferred choice of representation, it SHOULD include the specific URL for that representation in the Location field; user agents MAY use the Location field value for automatic redirection. This response is cachable unless indicated otherwise.