The HTTP 418 I'm a teapot client
error response code indicates that the server refuses to brew coffee
because it is, permanently, a teapot. A combined coffee/tea pot that is
temporarily out of coffee should instead return 503. This error is a
reference to Hyper Text Coffee Pot Control Protocol defined in 1998 and
2014.
Some websites use this response for requests they do not wish to handle, such as automated queries.