Notes
Trash
Deleted notes stay in the Trash
Deleting a note does not remove it right away. It moves to the Trash, so you can bring it back if you deleted it by mistake.
Bringing a note back
Open the Trash from the Notes screen, select the note, and move it back to a folder. Notes from a folder you deleted are in there too.
Deleting a locked folder is the exception — its notes do not go to the Trash. They are deleted outright and cannot be brought back. Locking a folder has the detail.
Deleting for good
Empty Trash is the point at which notes are actually removed. After that they cannot be recovered.
If you are emptying it to free up space, note that notes with photos go with it. Worth a quick look through first.
Not included in backups
Notes in the Trash are not included when you create a backup file. This keeps things you meant to delete from coming back through a restore.
If something in the Trash is worth keeping, put it back before making a backup.