The K is, of course, for König. The O is for Oberknabe (over-knave), and the U is for Unterknabe (underknave). The suits are Hearts, Acorns, Leaves, and Bells.

I'd never seen these before, or heard of them, ever. Cards have such an unusual history, tied in with the court cultures of their countries, but almost unreachable, sitting there in front of you, filled with references to your own cultural past that you'll probably never get. How many people realize the names of days come from pagan worship? (Sun, Moon, Tyr, Wodin, Thor, Freia, Saturn.) I tantalize myself with the thought that each of these symbols means something, but very few German people could ever tell me what.