By the way, the backwards rules are pretty consistent, despite being confusing: If you use the clues on the bottom-right, you can see that the canonical leftovers are, e.g., Drawer (d6) and Foe Carton (f9). These words don't need to make sense, since 12's category is "leftovers" not "parts of a message". Similarly, puzzle 0 can have words like "dew" because 0 has no category it needs to follow. I admit it's weird that these words only spell a message backwards (left-to-right) but it's consistent between puzzles 0 and 12 and I'm fairly confident it's better than the reverse (which I did try in an earlier version).