When Chang flashes Jeff's driver's license, Jeff Winger's date of birth is Nov 20, 1971, which also happens to be Joel McHale's actual birthday.
When Chang calls Star-Burns about the party at Jeff's, we see that his sideburns have been shaved into hearts. As in heart-burns.
First appearance of Magnitude.
Shirley is only in the first and last scene of the episode. She's the only character that doesn't branch away from the study group to have her own storyline.
Pierce is shown abusing his pain medication throughout the episode. Chevy Chase had a bad addiction to pain killers in the 1980's. In 1986, his addiction would lead him to seek treatment at the Betty Ford Center.