Levi's Jeans - What Did They Change?

Levi's jeans have not changed much over their history, but they did change what? A, they removed a metal rivet from the crotch because they would heat up and burn their customers when they sat next to a campfire. B, they started stitching two curved lines on the back pocket instead of Levi's Strauss's face. C, they added that tiny fifth pocket so that workers can break the ice with each other by asking "What do you think this little pocket is for?"