Iodoform gauze is a type of sterile, absorbent fabric used to pack wounds and facilitate blood clotting and general healing. In most cases it is materially identical to standard medical gauze except that it has been treated with or soaked in iodoform, an antiseptic.
GCWR takes into account GVWR and loaded trailer weight. The GCWR is the maximum weight the vehicle can carry and pull together. The loaded trailer weight plus the GVWR of the vehicle cannot exceed the GCWR as specified by the manufacturer.
The GVWR is the combined weight of your truck plus your load. For example, my C30 weighs in at about 5,800 lbs. (I think) My license plates are only good for up to 8,000 lbs. GVWR, so the max load I can carry legally is 2,200 lbs. in the bed of the truck before I risk a MAJOR fine for being over weight.