To ensure the traceability of a product, NPC assigns a product code and a lot number to each product, so that its process history can be traced. In addition to the above code and number, a date code inscribed on the surface of a package product helps trace the history of its assembly process. The method of assignment of the lot number and the date code is illustrated below. [Assigning method of the lot number]
A lot number of NPC is 9 digits long normally. The meaning of each digit is as follows:
[Assigning method of the date code (typical example)]
The date code assigned to a package product varies from 5 digits to 1 digit. Here is an example of a 4-digit date code.