Bottom row is empty... of course! Thank you Ordrosh and Nibelheim
This was bothering me when I was looking at the minimap icons and saw one giant image, and then someone asked about the class icons, which works on the same principle.
If I wanted the Warrior icon, I'd use 0/4, 1/4, 0, 3/4 correct? Or at least nearly enough that I could figure it out once I plug it into code.