GMC 2004 Sonoma Owner's Manual page 305

(D) Department of Transportation (DOT): The
Department of Transportation (DOT) code indicates that
the tire is in compliance with the U.S. Department of
Transportation Motor Vehicle Safety Standards.
(E) Tire Identification Number (TIN): The letters and
numbers following DOT code are the Tire Identification
Number (TIN). The TIN shows the manufacturer
and plant code, tire size, and date the tire was
manufactured. The TIN is molded onto both sides of the
tire, although only one side may have the date of
manufacture.
(F) Tire Ply Material: The type of cord and number of
plies in the sidewall and under the tread.
(G) Single Tire Maximum Load: Maximum load that
can be carried and the maximum pressure needed
to support that load when used as a single. For
information on recommended tire pressure see Inflation
- Tire Pressure on page 5-67 and Loading Your
Vehicle on page 4-45.
Compact Spare Tire Example
5-61