At one point, Jack tells Will not to be upset, because "It's not like you found out you were adopted... Or Canadian."
Eric McCormack (who plays Will) is, in fact, Canadian.
In syndication (Cozi TV, 2020) a line from Karen is muted out. In this dialogue, "sons of bitches" is edited out: "What the hell did you two Mork and Mindy-looking sons of bitches do to my cousin Barry? You're supposed to help him be gay, but you didn't finish. The poor kid's so confused, he's sitting at home on the couch watching football in a spandex onesie."
The guy on the cover of the Healthy Male magazine Barry presents to Will and Jack is the actor who plays Russell in Jack's acting class.