I have just returned from mass in a foul mood. On the way home I stood in a queue in my local shop while some assistant tried to find the bar code on a bottle of coke. The woman in front of me had brought her basket of goods to the till, had them checked through but the bottle of coke she had picked up had no code on it. the girl on the till had then to go to the shelves to find a bottle that had in order to scan it. While I initially was cheesed about the time this took I then got to thinking How does a bottle of coke without a bar code appear for sale on our shelves anyway. is this another example of shopkeepers duping the customer by opening special offer packs and selling them individually or is there an innocent explanation