This is the first dialogue and credited appearance for Ruth Cohen as the self-named cashier Ruthie Cohen at Monk's Diner. At this point, Cohen had already been visible as the cashier in over 50 episodes since The Trip: Part 1 (1992) (basically every episode which features the diner and uses the across-the-table camera angle that shows the register). Cohen would go on to have a few lines twice more--a credited appearance in one of those episodes--but in total she appeared in 101 episodes, making her by far the most frequent character in the show besides the main four.
Second appearance of Lloyd Braun, after The Non-Fat Yogurt. He is played by a different actor this time, as Peter Keleghan has been replaced by Matt McCoy.
Lloyd Braun, an ABC entertainment executive, lent his name to a character that appears in three episodes throughout the series: Season 5, Episode 7, The Non-Fat Yogurt (1993), this episode, and Season 9, Episode 3, The Serenity Now (1997), and is a neighbor and nemesis of George Costanza (Jason Alexander).
In this episode, Michael Richards' Kramer is described as having a "Raymond Massey like physique." Many years later, Richards would play the character Jonathan Brewster in a London stage production of "Arsenic and Old Lace," the same part in the movie version played by Massey.