Trivia: The episode starts off with Dee Dee eating scraps, while Marky looks over stuff. Later on, Marky found what seems to be an Identity Card that belongs to Joey. Here, the card shows that Joey's birthday is on June 15th, 1991. (00:00:14)
Suggested correction: Is there some sort of special offscreen significance to this birthday? Because I don't see how this constitutes trivia if it's blatantly shown onscreen.
It counts as a trivia because no characters except Joey have their dates of birth revealed.
I mean, unless I'm lacking some sort of other context, I still don't think just seeing a character's birthday counts as trivia, unless the date is some sort of inside joke or reference.