You probably noticed from the schematic that each display is fitted with a half-bridge of transistors. This allows for installing both CC and CA displays on the motherboard. You just have to be careful not to populate both of them. If you use a Common Anode (CA) display, you will have to populate the high side driver transistor and vice versa. 

In my case I used CC displays and I populated the Qxxx_B side of the half bridges as seen in the image: