Something that everyone knows really did happen, but pretends never did, because it was so awful, or everyone is in denial
Norton: How was Easter brunch with your fiance's entire family, including the crazy ones?
Kramden: Highlander Two, dude. Never happened.
Norton: But I saw it on the news, there was a fight, and a fire...
Kramden: Highlander Two!
Norton: And the helicopters, and the swat team...
Kramden: HIGHLANDER TWO!