Marcia Wallace who voiced Edna Krabappel for 25 years died a week before this episode aired. As a tribute in the opening chalkboard punishment scene Bart is looking forlornly at a single chalkboard line "We'll really miss you, Mrs. K." breaking the tradition of having multiple lines on the chalkboard in the opening title sequence.
Reveals the origins of the Springfield Tire Fire.
The Apple Corporation is normally referred to within the Simpsons universe as Mapple (MyPods, MyPhones, founder Steve Mobs, etc). This episode, however, uses the real names for the company and its products this is the first instance of a product in the Simpsons universe being referred to by their real names instead of a parody.
The notice board by Chip's casket in the opening scene reads: "Chip Davis, Beloved Husband, Father, Town Meeting Attendee, Duffman 1992-1996, 2008, Proofreader for Springfield Sign, Sideshow Chip, Dome-Shards Removal Supervisor." (This last line obviously referencing the aftermath of The Simpsons Movie (2007)).
While trying to find the engagement ring for Lila, Mr. Burns pulls out the monkey paw from Treehouse of Horror II (1991).