PTT was the former state telephone company in the Netherlands, and the sharp bell ring from its rotary-era telephones became a familiar household sound for generations of Dutch callers. As those phones were replaced by mobile tones, the ring survived online as a shorthand for an old-fashioned call, shared on soundboards for retro edits, comedy sketches and nostalgic videos. It remains popular because it is instantly recognisable, even to viewers who never owned one, and it immediately sets a scene in a time before smartphones.