GCWR
Gross combination weight rating: truck, people, cargo, and trailer together.
GCWR is the ceiling for the whole combination. The published trailer weight is what remains after the truck and the test's assumed occupants are accounted for. Chevrolet prints GCWR next to each Silverado trailering cell. Ford does the same.
If you add passengers or bed cargo, you are not allowed to keep the full trailer weight and still claim the GCWR. Something has to come off the trailer.