418 I'm a teapot
loreweb devops culture
Stands for: Hyper Text Coffee Pot Control Protocol (HTCPCP)
An April Fools' HTTP status code, defined in 1998, returned by a teapot asked to brew coffee.
RFC 2324 invented the Hyper Text Coffee Pot Control Protocol and its 418 status as a joke, but the code took on a life of its own and is widely implemented as an Easter egg. Attempts to remove 418 from real frameworks in 2017 provoked enough backlash that it was kept and later reserved by the IETF.
HTTP status 418 I'm a teapot comes from RFC 2324, the Hyper Text Coffee Pot Control Protocol, published as an April Fools joke in 1998. The status is returned by a teapot asked to brew coffee, and it has been implemented, entirely unnecessarily, in a great many real HTTP libraries and frameworks.
Its subsequent history is the interesting part. In 2017 a proposal to remove it from implementations, on the reasonable grounds that a joke status occupying a real code point is untidy, met a coordinated and effective campaign to keep it. The argument that won was not technical: 418 had become a piece of shared culture, a marker that the people building the web knew it was built by people.
There is a genuine lesson underneath the silliness. Reserved and unusual code points get used, so a specification that leaves room for humour has to accept that the humour becomes load-bearing, and 418 now cannot be safely reassigned to anything serious. The IETF eventually reserved it explicitly to prevent exactly that, which is the most bureaucratically satisfying possible ending to a joke about teapots.
Also known as: HTCPCP, I'm a teapot, HTTP 418