It usually appears at the most inconvenient moment so since I have a spare five minutes, I thought I’d find out what it actually means. 404 is a hypertext transfer protocol (http) standard response code indicating that a request for a uniform resource locator (url) has been made but that no such resource exists. Or in non-technical terms it means that the address of the website page you typed in cannot be found.
As well as the 404 error, I found a heap of other codes in the 400 range such as 407 (proxy authentication required), 401 (unauthorised), 415 (unsupported media type), or 408 (request timeout). But by far the strangest were:
- 406 (not acceptable) – The HTCPCP server is unable to brew coffee for some reason; the response should indicate a list of acceptable coffee types; and
- 418 (I’m a teapot) – The HTCPCP server is a teapot; the responding entity may be short and stout.
Apparently every year the Internet Engineering Taskforce publish a Request for Comment on 1 April. In 1998 it was the Hypertext Coffee Pot Control Protocol (HTCPCP for short) which is a protocol for controlling, monitoring, and diagnosing coffee pots. It makes interesting reading as does last year’s RFC IANA considerations for three letter acronyms.