Appropriate footwear is defined as a boot that covers the foot and ankle and that is constructed with a suitable sole and upper portion. The upper portion of the boot should provide protection from penetration. The sole should provide proper traction for work on the ground as well as when working aloft.
I seem to remember seeing Mark C at older comps sporting some nike b ball shoes. They cover the ankle and have a great sole. Aren't boot like though...must be new terminology with a recent rule change?