Johnny Carson knew it the first time he walked up on the stage of the Tonight Show in 1983. Seinfeld got the O.K. sign [0]: https://www.youtube.com/watch?v=Q_4

Johnny Carson knew it the first time he walked up on the stage of the Tonight Show in 1983. Seinfeld got the O.K. sign [0]: https://www.youtube.com/watch?v=Q_4ds9BtQEI https://www.youtube.com/watch?v=Q_4ds9BtQEI [0] https://www.nytimes.com/2005/01/30/arts/television/carsons-code.html https://www.nytimes.com/2005/01/30/arts/television/carsons-c...