Yes. 4xx codes are client errors: The request contains a mistake or can't be fulfilled as sent.

4xx · Client error

HTTP 418 I'm a teapot

An April Fools' joke from RFC 2324: the server refuses to brew coffee because it is a teapot. Some services use it as a playful block.

Example response

HTTP

HTTP/1.1 418 I'm a teapot
Content-Type: application/json; charset=utf-8

{ "error": "I'm a teapot" }

Look up the headers shown here in the HTTP headers reference.

What does HTTP 418 mean?: I'm a teapot. An April Fools' joke from RFC 2324: the server refuses to brew coffee because it is a teapot. Some services use it as a playful block.
Is 418 an error?: Yes. 4xx codes are client errors: The request contains a mistake or can't be fulfilled as sent.