A Lot Number is a number which is unique for the single lot.
The Lot Number consists of nine digits. If the lot has been divided into more lots, the Lot Number will get two additional digits.
The Lot Number is built as follows:
The first four digits in the Lot Number (xxxx) are the SKU Code, i.e. the code that is linked to the Stock Keeping Unit (SKU).
The next five digits (yyyyy) are the actual Lot Number, which is unique for the Lot. You can use this part of the Lot Number without the first four digits (the SKU Code), if you need to have your Lot Number in a short version.
The last two digits(zz) are only added to the Lot Number in the occassion that the Lot is divided into more Lots. In that case, the five digits in the center of the Lot Number (yyyyy) will remain the same, but the new Lots will have two additional consecutive, digits (zz) added to the Lot Number. Thus, it is apparent that the new Lots once have been part of the same Lot.