What methods of creating the secrete code tags for put on product by shopkeepers.?

[Manoj_Kumar]

In Haryana many shopkeepers puts the secrete code tags on their product. The secrete code tags are of various types i.e. Numeric code 128005, alphabetic code SDR etc. The code tag consist the purchase cost/sale cost of the product. It is clear that purpose of such types of code tags is to hide information of cost from customer. I want to know that how they create the code. How they find the cost of product by codes. Tell logic about it. Tell the some methods of creating such type of codes.