Yes, that is one of the few rare pictures showing how the cod piece and butt plate attach. Here is a condensed version of the pic in BountyHunter185's link.
That's the pic I have. I just sold a set of bolts on ebay, and was asked where they go. All I have is that pic, and I don't actually use them. The girth covers that part for me, anyway.
yeah my belts cover that part of the cod, but thats how I attach my cod & butt plate(ha butt plate)...I screwed those 2 pieces together using that, and velcro on the inside.