Lately I've got a lot of questions about 1D barcodes (a common 1D barcode is the barcode you find on any item at the local grocery store) both via e-mail and on certain forums. A lot of people are wondering why it's so hard to find a cell phone barcode scanner that supports 1D barcodes. A lot of people also are under the impression that 1D barcodes contain some sort of "secret" information. The truth however is that they only contain the same serial number you see below the code. I'm going to post the last question and my reply here.
QUESTION: [...] reading a normal barcode like those series of lines you see when you buy a potato chips, or whatever product that has a barcode with numbers below it. I tested it and it doesnt work. Nokia [barcode reader] seems to read it but i though its useless because it just copies the number below the bar and it doesnt mean anything.
It actually worked perfectly. A 1D barcode (like the UPC EAN codes found on merchandise in the store) only contains numbers. They only contain the same number printed below the code. The printed numbers are there so that the number can be manually punched if the barcode is damaged. Some 1D codes can contain certain ASCII letters, but these are mainly used on transport invoices, etc.
I'll try to explain how these barcodes work. When the barcodes is scanned at the cash register, the cash register reads the numbers within the barcode (the same numbers that are printed below). These numbers are the items "serial code". The cash register then queries the stores database, and the items price, vat, name, etc are returned.
The reason for this is that it would be totally useless to store any of this information in the barcode. That would mean that all the barcodes would have to be replaced every time a product changed price (taking away the whole point of barcodes on products). It would also mean that one would have to have different barcodes for the exact same product in different countries.
It's a quite common misunderstanding that the barcodes on products in the store hide all sorts of "secret" information. They only contain the same number that's printed below the barcode. Anything else is stored in the stores database.
This is also the reason there basically aren't any 1D barcode readers for mobile phones. Being able to scan 1D barcodes is useless unless you have access to a back-end database containing info about the barcodes you are scanning.