100-199 (silent) SRCs provide confirmation that a Request was received and is being processed.
100 This is good. The Request was completed and the process can move along.
101 Request to switch protocols (like from HTTP to FTP) was accepted.
200-299 (silent) SRCs report that Requests were performed successfully.
200 It simply means all is okay. What the client Requested is available.
201 This means a new address was successfully created through a CGI or posting form data.
202 The client's Request was accepted, although not yet acted upon.
203 The accepted information in the entity Header is not from the original Server, but from a third party.
204 There is no Content in the Requested click. If you click on an image map section not attached to a Page. This allows the Server to just sit there waiting for another click rather than throwing an Error.
205 This allows the Server to reset the Content returned by a CGI.
206 Only partial Content is being returned for some reason.
300-399 (usually silent) Request was not performed, but a redirection is occurring.
300 The Requested address refers to more than one entity. Depending on how the Server is configured, you get an Error or a choice of which Page you want.
301 Page has been moved permanently, and the new URL is available. You should be sent there by the Server.
302 Page has been moved temporarily, and the new URL is available. You should be sent there by the Server.
303 This is a "see other" SRC. Data is somewhere else and the GET method is used to retrieve it.
304 This is a "Not Modified" SRC. If the Header in the Request asks "If Modified Since", this will return how long it's been since the Page was updated.
305 This tells the Server the Requested document must be accessed by using the proxy in the Location Header (i.e., ftp, http).
307 The requested URI has moved, but only temporarily. The Location header specifies the new location, but no information is given about the validity of the redirect inn the future. The client should use the revisit the original URI in the future.
400-499 Request is incomplete for some reason.
400 There is a syntax Error in the Request. It is denied.
401 The Header in your Request did not contain the correct authorization Codes. You cannot see what you Requested.
402 Payment is required. It's not in use yet.
403 You are forbidden to see the document you Requested. It can also mean that the Server doesn't have the ability to show you what you want to see.
404 Document not found. The Page you want is not on the Server nor has it ever been on the Server. You may have misspelled the title or used an incorrect capitalization pattern in the URL. e.g. A web page spells a graphic file name in capitals but the graphic filename is lowercase. Another reason is the absence of a favicon.
405 The method you are using to access the File is not allowed.
406 The Page you are Requesting exists but you cannot see it because your own system doesn't understand the format the Page is configured for.
407 The Request must be authorized before it can take place.
408 The Request timed out. For some reason the Server took too much time processing your Request. Net congestion is the most likely reason.
409 Conflict. Too many people wanted the same File at the same time. Server overload. Try again.
410 The Page used to be there, but now it's gone.
411 Your Request is missing a Content-Length Header.
412 The Page you Requested has some sort of precondition set up. That means that if something is a certain way, you can have the Page. If you get a 412, that condition was not met.
413 Too big. What you Requested is just too big to process.
414 The URL you entered is too long.
415 The Page is an unsupported media type, like a proprietary File made specifically for a certain program.
416 The requested byte range is not available and is out of bounds.
417 The server is unable to meet the demands of the Except header given by the client.
500-599 Errors have occurred in the Server itself.
500 No associated user.
501 What you Requested of the Server cannot be done by the Server.
502 Your Server has received Errors from the Server you are trying to reach. The "Bad Gateway" Error.
503 The format or service you are Requesting is temporarily unavailable.
504 The gateway has timed out. Similar to 408 Error except that the time-out occurred specifically at the gateway of the Server.