The pickers are directed to choose a location and are required to provide a
check digit to confirm that they are at the correct pick location, and the system then tells them the quantity of units to pick.
Because one of the digits is a "
check digit" in theory there could be as many as one billion different NPIs.
"For lower level security, we might print a modulus number sequence with
check digit," says Philip Easton, director of digital printing solutions at Domino Printing Sciences.
After reading back a
check digit, they are told how many items to pick to one of 16 orders on the cart.
But the new number had a feature which made it superior to the traditional ISBN: Emery Koltay (at that time director of standards at Bowker, New York) designed a
check digit calculation routine that allowed turning an ISMN into a bar code without further calculation, just by adding the EAN code "979" in front.
Furthermore, the International Organization for Standardization published ISO/IEC 7064 to define algorithms for calculating
check digit which is used in the IBAN.
It has a secured pin code which is known by the user only, and also has a
check digit without it no one can deposit money.
At each pick location, pickers read back a
check digit on the location label to confirm that they are at the correct location and confirm that they put the product on the correct pallet by reading the
check digit on one of the two pallets.
Each UNII is a unique series of ten characters that includes a
check digit to ensure data integrity.
The first component is comprised of a country code and
check digit and the 2nd component is called Basic Bank Account Number (BBAN).