Backstage Canon

"Backstage Canon" refers to scenes or scenarios where characters are being themselves but OOC while still in the In-character environment.

The easiest example of this is Deadpool whenever he breaks the fourth wall, but even more s like the Evangelion characters in the Evangelion Radio Play.

Basically it's your characters being able to be meta about the setting and environment, such as when Xadium complains about the box topic or something like that while in the box.

It's basically the entire premise of the SS4 channel in the chatbox unless used for an in-box-canon event.

If an event is happening under "Backstage Canon Rules" it means that for the duration of the event what happens is not in-box continuity but in its own separate metafictional continuity.