Per the title, the Ruptured Duck was slang for the Honorable Service Lapel Button awarded to United States military service members who were discharged during and after World War II.
S. Peter Pryor Junior College, which is introduced in this episode and which will serve as the primary setting of the series' last two seasons, is often presented as a small rural college, but according to this episode it boasts at least nine different buildings: The Administration Building, the Amateau Building, the Student Union, Burton Hall, Jaffe Hall, Vincent Hall, Murphy Hall, Millard Hall, and Pattee Hall.
S. Peter Pryor was actually Max Schulman's accountant.
With the setting of the show shifting from the Army to Pryor Junior College, Dobie changes during the first "Thinker" monologue out of his Army uniform and into civilian clothes.
First appearance of Dean Magruder.