1. Computer-readable storage media embodying a program of instructions which, when executed by a computer system, causes the computer system to perform a specific two pass process for Harmonized Tariff Schedule (HTS) classifications using a software user interface to an electronic database system for storing and classifying HTS codes for imported products, the two-pass process comprising: providing information to a first person which permits the first person to classify each of the products with an HTS code using the software user interface at a first terminal, the information not including U.S. Customs rulings; receiving from the first person a classification of each of the products, including an assignment of an HTS code to each of the products, based on the provided information, through the software user interface at the first terminal; receiving from the first person an explanation for why the first person decided to classify each of the products with the HTS code which the first person assigned to each of the products through the software user interface at the first terminal, the explanation being in addition to each assigned HTS code storing each assignment of an HTS code and each explanation for each assignment within a classification repository of the electronic database system; providing to a second person different from the first person, after the storing of each assignment and each explanation by the first person, access to each assignment of an HTS code and each explanation for each assignment in the classification repository through the software user interface at a second terminal different from the first terminal, along with U.S. Customs rulings and other information pertinent to classifying each of the products with an HTS code, the second person having a level of customs classification qualifications higher than the first person; receiving from the second person an identification of at least one error in the assignment of an HTS code to a product by the first person through the software user interface at the second terminal based on a review by the second person of the HTS code and the explanation for the assignment of the HTS code; and receiving from the second person and entering into the classification repository a change to the erroneous HTS code that was assigned to the product by the first person through the software user interface at the second terminal.