GMC 2004 Sierra 1500 Pickup Owner's Manual page 478

(F) Uniform Tire Quality Grading (UTQG): Tire
manufacturers are required to grade tires based on three
performance factors: treadwear, traction and
temperature resistance. For more information, see
Uniform Tire Quality Grading on page 5-90 .
(G) Maximum Cold Inflation Load Limit: Maximum
load that can be carried and the maximum pressure
needed to support that load. For information on
recommended tire pressure see Inflation - Tire Pressure
on page 5-84 and Loading Your Vehicle on page 4-57 .
LT-Metric Tire
5-78