We also had a similar system in Turkey too, with local grocery shops. The owner would have two notebooks per customer, one would stay at the store and one would

We also had a similar system in Turkey too, with local grocery shops. The owner would have two notebooks per customer, one would stay at the store and one would be given to customer. Whenever you needed to buy something but you wanted to pay later, the merchant would put the transaction on his notebook with a copy on your notebook, so at the end of the month you would simply bring your notebook and cross reference the transactions and pay your debt.