Hey, Rules Guy: The other day, my friend was in a valley 50 yards from the green. He couldn't see the flag, so he ran up the hill to find the line and placed his hat at the top of the hill as a marker. He then hit his shot over the hat and onto the green. Is that allowed?
— Scott, Carl Junction, Mo.
No, it's not, and my hat's off to you if you enforced the correct penalty: two strokes (or loss of hole in match play) under Rule 8–2, which governs alignment aids. It's actually okay to put the hat down; in fact, from off the green you can line up with any aid you want — clubs, caddies, whatever. The penalty comes from leaving it on the ground when you strike the ball. You can't hit a shot with the aid in place.