<s>[INST] The picking list for a small mail-order business is printed on preprinted forms with the header material shaded, and the shaded region includes 6 lines for writing (not for headers). The picking list is divided into columns including columns for the item number, quantity, and titles. It is known that only two columns contain numbers. It is also known that 22 rows down from the header in the shaded region there are four fields on that row which are filled with data which gets repeated. These four fields are evenly spaced out and contain the item numbers, ‘71779’, ‘78602’, ‘84763’ and ‘89110’, all of which start and end with the same digit, and have their unique digits placed between them in the order shown. This task is needed to identify the actual organisational or structural pattern behind creation of these special codes.[/INST]