The following shipment types are used for goods entering United States via highway carrier:

PAPS – default shipment type for commercial goods entering the U.S., allows pre-clearance of goods.
In-Bond – allows for inland movement of goods that are not considered “released” by CBP.
Section 321 – allows for import of goods valued under 800 USD.
IIT – used for empty racks and containers that cross the border in international transportation.
ATA Carnet – type of temporary import.
BRASS – type of pre-clearance, can only be used by FAST-approved drivers. (phasing out).
Personal Shipment (3299) – used when non-commercial goods are transported by highway carriers.
Free of Duty (7523) – used for duty free merchandise not exceeding 2000 USD in value.
Returned American Products (3311) – type of informal entry that allows for the release of shipments of products of the United States being returned.
Goods Astray – used for the return to the U.S. of refused or undeliverable shipments or goods brought into Canada accidentally.
International Mail – used to report shipments of mail moving from a foreign postal service to the U.S. Postal Service.
Intangibles – used for the release of certain specific commodities including business records and articles returned from space.