A traceability lot code is the identifier that ties a lot of food to its records under the FDA's Food Traceability Rule. It is assigned at specific points, such as initial packing, first land-based receiving of seafood, or transformation, and then passed along with the food.
A distributor that only receives and ships a food usually keeps the code it was given; one that repacks or transforms a food assigns a new one and records the link to the inputs.
In APFoodz every lot carries a traceability lot code alongside the packer's own.
Source: FDA: Food Traceability Rule