During the dinner scene, Melissa mentions to Rachel that her boyfriend went to Syracuse University and was a brother of Theta Beta Pi, which does not exist. However, the university used to have a Beta Theta Pi chapter which has been inactive since 2000.
In this episode, Joey mentions that Chandlers parents are going. However, at this time, Monica thought Chandler had invited his father, but it isn't until S7 Ep22, The One With Chandler's Dad, that Chandler tells Monica he didn't invite his father when she mentions they've not received his reply card.