Importer Security Filing is commonly known as 10+2 initiative which CBP regulates that requires importers and carriers to provide additional advance data to CBP for containerized cargo shipments arriving at U.S. by vessel. 

Importer Requirements: (ISF 10)

US Bound Cargo – requires 10 data elements.

Carrier Requirements: (+2)

1. Vessel Stow Plan (VSP) – required for containers arriving. A plan showing the distribution of all cargo parcels stored on board of a vessel for a voyage. It represents the quantities and description of the various grades carried in the ship cargo tanks after the loading is completed.
2. Container Status Messages(CSM) – required for containers arriving via vessels. Carriers must submit CSM when there are events that happened on the container destined to arrive in the U.S. by vessel. CSMs are also required for empty containers.