KZ = Transit
S= Storage
When a vehicle is signed off after it has been assembled
It could be going to the Body Vendor, for Ordered parts that don't get installed on the assembly line
Between the Assembly Line & transit to the Body Vendor, there is a Storage period, while waiting for the semi truck to pick it up.
When your Ram returns to the Assembly Line Property. it is in Storage while waiting to be loaded on a truck or freight car
When the Ram reaches your local Rail Freight Yard, it goes to Storage again, while waiting for a semi truck to haul it to the dealership