GMC YUKON 2017 Owner's Manual page 124

Storage 123
Do not exceed the maximum vehicle
capacity when loading the vehicle.
For more information on vehicle
capacity and loading, see Vehicle
Load Limits 0 212.
A Center High-Mounted Stoplamp
(CHMSL) is located above the rear
window glass. Make sure items
loaded on the roof of the vehicle do
not block or damage the CHMSL.