My favorite http status code has to be 418. Look it up, thank me later.

Internet engineering task force 1998 April fool's joke.

For the lazy

"418 I'm a teapot (RFC 2324)
This code was defined in 1998 as one of the traditional IETF April Fools' jokes, in RFC 2324, Hyper Text Coffee Pot Control Protocol, and is not expected to be implemented by actual HTTP servers. The RFC specifies this code should be returned by teapots requested to brew coffee."

@vtepe I totally agree.

@eldamir > ...and is not expected to be implemented by actual HTTP servers. The RFC specifies this code should be returned by teapots requested to brew coffee

I know what my next project is.

POST my-coffee.com
CONTENT-TYPE application/json

{
"Brew_it": "now"
}

<-- 418 I'm a teapot

When at first it was a joke then it's use case becomes relevant in the future