Adapting to changes

My parents own a small trading business, they sell assorted goods to wet markets and small grocery stores in nearby towns. Last week my sister informed me that they are now required to adapt the bar code system since some of their client has started using barcode scanners. She managed to get some help and was able to get the application forms from GS1 Philippines Inc. A few days after the forms were submitted, my sister finally received the documents bearing the assigned bar code number.

Everyday we see bar codes everywhere and i believe each bar codes are unique for every manufacturer/seller nationwide. I wonder how they came up with each of the codes and figures like the one shown here. Oh well my sister will attend a seminar at GS1 Philippines Inc. this afternoon, maybe after that seminar she can answer all the questions i have in mind.