"The Puffy Shirt" was the second episode of Seinfeld's fifth season. Because of a misunderstanding, Jerry agrees to wear a puffy shirt, designed by Kramer's girlfriend Leslie, for his nationally televised interview. The interview is a disaster because Bryant Gumbel can't stop laughing at the shirt.

Jerry's fascination with the number nine factored into his decision to end Seinfeld after nine seasons. "Nine is cool," he says. "By the end, we will have done 180 shows (1+8=9). When I was thinking about quitting the show, I thought, nine. People said, '10--why not 10?' But 10 is lame. Nine is my number."

Jerry tells Elaine that six would be fine for a phone break-up, but seven has to be a face-to-face break-up unless she hasn't had sex with the guy.

In the episode "The Strong Box", Kramer says one of the things in his strongbox is his military discharge. Upon being asked, "You were in the Army?", Kramer replies, "Briefly," and claims the reason for his discharge is classified.

Jerry dares her $50 to take an egg roll from someone's plate and eat it. Elaine approaches a table and offers to split the $50 with them, but she speaks too softly. When they can't understand her, she panics and retreats.

Jerry is a stand-up comedian (like the real Seinfeld) throughout the series.

Newman is caught in a compromising position with Kramer's mother, Babs, after Kramer, Elaine, and George walked into his apartment at the end of "The Switch".

Jerry names his favourite yellow t-shirt "Golden Boy". Unfortunately, "Golden Boy" is so old that he is dying. At the end of the episode, Jerry tells Elaine that he didn't make it through the final wash cycle and has been replaced by his son, "Baby Blue".

Her father's career as an author may have been the inspiration for Elaine to grow up and work as an editor at Pendant Publishing.

Jerry's mother Helen greets Newman in the same way.