I'm not sure about the status after delivery, but the note that a parcel needed SOD stopped printing on labels (through My Post, anyway) years ago. When people asked Aus Post why, they said it was to try and stop the delivery guys sorting packages by which ones needed it or not, and automatically carding those ones instead of attempting delivery, because it only comes up that a sig is required when they scan it. (I have NFI if that's true or not, seems plausible, though).
