Postcards from the Wedge/References

Cultural references

 * The episode title:
 * Is a pun on the Postcards from the Edge, which was based on the  by.
 * Refers to the term "", which is an issue that is divisive by nature and so can put otherwise like-minded people at odds with each other, as seen in Bart's manipulating Homer and Marge to play them against each other.
 * The Itchy & Scratchy cartoon, "Mouse, M.D.", is a parody of House M.D.
 * The anime cartoon that Bart watches is a parody of Pokémon. Additionally this episode also aired on the same day that, the remakes of the games  were released on the  in the United States.
 * The film Springfield of Tomorrow (shown at the beginning) contains some classic cartoon sound effects, such as the "pbpbpbpbpbpbpbpb" motors from The Jetsons and the trombone talking of the teachers in the Peanuts television specials.
 * The music being played in the film strip and during the credits is 's "".
 * Bart and Milhouse both make  references when they discover the subway.
 * Mrs. Krabappel says that Bart ruined every ideal she had about teaching since she saw the movie  as a little girl.
 * Moe's Express is a parody of.

Trivia

 * In this episode, the flag pole is as tall as the school.
 * This episode features the show's first ever true grounding, and the first to stand for the rest of the episode. Prior to this episode, Bart and other children would be sent to their rooms, or punished in other ways. This episode is the culmination of the increase in groundings that started in season 20, with more groundings being used in seasons 20-21 than the previous 19 seasons put together.

Continuity

 * The term "wedge issue" is also punned in the title of the comic story Wedgie Issue.

Goofs

 * About 8 minutes into the episode, Lisa's pearls briefly appear red like Marge's, a goof commonly seen in episodes. In this episode, it's during the scene where Lisa explains fractions to Bart.
 * When Lisa was explaining her example fraction equation's answer, it is incorrect. 1/2 + 1/3 does not equal 3/anything. It equals 5/6 minimum. However, she could've meant 3/6 + 2/6 instead.
 * Although the subway system is abandoned, it is still used in various couch gags.
 * Strangly, Fallout Boy appears on the cover of the Radioactive Man 8 comic book. But according to Three Men and a Comic Book, Fallout Boy didn't appear until the next issue, Radioactive Man 9.