Centerline Rims and Tires

They're four digits, two for number of the week, and the last two are the year.
There's usually several sets of three, four digits, and the Date Code will be the last four.
Ex: SG4T 00T2 GKT1 1220
The 1220 will be the 12th week of 2020.
They're normally on the BSW side of the tire.