Are Barcodes in Supermarkets Globally Unique and How Are They Tracked?
The barcodes used in supermarkets, specifically Universal Product Codes (UPCs) and European Article Numbers (EANs), are designed to be globally unique for each item. Let's delve into how these barcodes work, the total address space available, the potential for such codes to run out, and how your purchases can be tracked to specific items.
Global Uniqueness of Barcodes
Barcodes like UPC and EAN are used to uniquely identify products in supermarkets. Each barcode is structured with a specific format to ensure global uniqueness.
UPC and EAN Structure
UPCs typically consist of 12 digits, while EANs have 13 digits. The structure of these barcodes is as follows:
The first few digits generally indicate the manufacturer. The following digits represent the item number. The final digit is the check digit, used to verify the accuracy of the barcode.This structure ensures that each product in different manufacturers' catalogs can be uniquely identified, leading to globally unique barcodes.
Global Standards and Management
The global management and assignment of these barcodes are handled by GS1, an organization dedicated to ensuring the uniqueness of barcodes across different products and manufacturers.
Total Address Space
The vast address space available for both UPCs and EANs makes it unlikely that they will run out soon, even in high-volume scenarios like a 2K type scenario.
Address Space Calculation
Let's break down the address space:
UPCs consist of 12 digits, giving a total of (10^{12}) (1 trillion) possible combinations. EANs, with 13 digits, offer (10^{13}) (10 trillion) possible combinations.Given these massive numbers, the address space for both UPCs and EANs is substantial, preventing them from running out anytime soon.
2K Scenario - Systems Handling Dates Beyond 2000
The 2K problem refers to systems that may not handle dates beyond the year 2000. However, the barcode system is not date-dependent, making it immune to this issue. Nonetheless, as more products are created, manufacturers need to ensure that they register new items with unique codes to avoid duplication.
Tracking Purchases to Specific Items
When you make a purchase, the barcode scanned at the register corresponds to a specific item in the retailer's inventory system. Here's how this tracking works:
Sales Data
Retailers can track which items are sold when and in what quantities.
Customer Tracking
If you provide a loyalty card or sign up for a membership, your purchases can be linked to your account, enabling detailed tracking of your buying habits.
Privacy Considerations
While items can be tracked down to specific products, privacy regulations like the General Data Protection Regulation (GDPR) in Europe govern how this data can be used and shared. Retailers typically aggregate this data for market analysis rather than tracking individual purchases without consent.
Conclusion
In conclusion, the barcode system is robust with a large address space that is unlikely to run out soon. Your purchases may be tracked to specific items, especially with loyalty programs, but this is subject to privacy laws and retailer policies. Understanding these aspects can help in managing the vast data generated by these coding systems in supermarkets.