After the Steven's dorm is vandalized by the fraternity he quit, the words "GREEKS NOT FREAKS" can be seen spray painted on the wall. Judd Apatow's previous sitcom, Freaks and Geeks (1999), starred many of the same actors.
Tina refers to Rachel having "caught the Freshman fifteen", which refers to a student's gain in fifteen pounds weight in their first year in college of university.