HTTP 418 – I'm a teapot
A joke response code from an April Fools RFC, sometimes used by servers that refuse to brew coffee.
Common use case
Occasionally used tongue-in-cheek by developers to mark endpoints as intentionally unavailable, or by anti-bot systems that don't want to reveal a real reason for a block.
History
Introduced in RFC 2324 (1998), the "Hyper Text Coffee Pot Control Protocol" - an April Fools' Day joke RFC that has never been withdrawn.
Did you know?
It was reaffirmed rather than removed in RFC 9110 (2022), and services like Google Cloud and GitHub's API have both used it playfully in real endpoints.