Room 404

404 is a http response status code. The common story that "404" was named after a specific room on CERN's fourth floor where files were manually retrieved is a myth.

Though it is a popular internet myth. The "404 Not Found" error originated from a system designed by Tim Berners-Lee and Robert Cailliau, who created a numerical system for error codes. The "404" was assigned to "not found" status by random programmer choice, and Cailliau has explicitly stated the number was not linked to a physical room at the facility, debunking the myth that it referred to a server room on the fourth floor.