A scenario that no longer has a purpose can be archived without being lost: it disappears from the current list, and stays recoverable.
Archive
From your group's scenarios page, archive a scenario that's no longer useful. It's then removed from the default list, without being deleted.
Restore
An archived scenario can be restored at any time: it reappears in your library, just as it was.
This action is reserved for admins. Trainers don't see archiving.