The Rp1 label comes from its upload on a user-generated soundboard rather than a named film, game or television programme, and no specific locomotive or recording session is identified in its listing. That ambiguity is common for short railway effects shared online, where the value is the recognisable sound itself rather than its source. Creators keep reusing it because a passing train is instantly understood across languages and formats, from travel edits and transit jokes to background texture in short-form video.