I just learned this at work. We have to scan our name tag which has our barcode on it when we give meds.
If you forgot your name tag at home you can generate one at work by going to this link and printing it up.
 
Now think about it. They have your personal number in a bar code. The computer knows who you are individually.
They got your number and it is a bar code, a binomial coding system. As shown many years ago there are 3 6's encoded into the bar code. It appears the next step is to implant that code and also to have some visible mark.
 
THis is the web site you can go to for printing your own barcode.
 
http://www.barcodesinc.com/generator/