Completely off topic and falling within the realm of totally useless information related to the all powerful OZ. Patricia mentioned something to me after the past MD meet about how the after market Z emblem some folks are rocking looks just like the OZ symbol from the original L. Frank Baum series of books.
I had to go check and sure enough they are very similar. Specifically, when you look at many of the illustrations that accompanied the series of books, particularly, "Ozma of OZ" and others, you'll see the familiar to us Z symbol.
Here is the front emblem:
Here are the L. Frank Baum OZ book illustrations:
