Kevin, you guessed properly about the top rack. I'm not sure how I can explain how the buttons worked. Definitely not rocker. You depressed the bottom end of it to select a different cycle. That button then went down and was "down" all the way up almost to the top compared to the button parallel to it. The buttons for this were Rinse & Hold, Light Wash, Normal Wash, Sani-Wash. INcidentally, that roto top rack was adjustable to two heights for larger plates or taller glasses. If glasses were too tall, they'd bump the metal track that went form the middle to the back of the machine (used for sliding the rrack in & out) and thus once a glass hit that track, rotation would cease.