GMC 1994 Sonoma Owner's Manual page 265

Payload
The Payload Capacity is shown on the CertificatiodTire label. This is the
maximum load capacity that your vehicle can carry. Be sure to include the
weight of the people inside as part of your load. If you added any
accessories or equipment after your vehicle left the factory, remember to
subtract the weight of these things from the payload. Your dealer can help
you with this.
Trailering Package
If your vehicle comes with the Trailering Package, there is also a load rating
which includes the weight of the vehicle and the trailer it tows. This rating
is called the Gross Combination Weight Rating (GCWR).
When you weigh your trailer, be sure to include the weight of everything
you put in it. And, remember to figure the weight of the people inside as
part of your load.
Your dealer can help you determine your GCWR.
Add-on Equipment
When you carry removable items, you may need to put a limit on how many
people you carry inside your vehicle. Be sure to weigh your vehicle before
you buy and install the new equipment.
NOTICE:
Your warranty doesn't cover parts or components that fail
because
of
overloading.