In this episode, a feud erupts between Larry David and Jason Alexander over a pen. In the Seinfeld (1989) episode The Pen (1991), Jason Alexander's character George doesn't appear in the episode at all. Jason Alexander was very angry with Larry David for not including George in the episode and threatened to quit the show, so there was a televised feud between Larry and Jason in Curb Your Enthusiasm (2000) over a pen, and a real-life feud between Larry and Jason over "The Pen".
Michael Richards is worried he might have Groat's Disease. Groat's is a made-up medical condition from The Thong (2001).