What does Signature strip mean?

The signature strip is that area on the back of a credit card assigned for placing your signature on it. This is yet another safety feature which is necessary, so that unauthorized use of your credit card is prohibited. Right above this signature strip, there you can find the message ‘not valid unless signed’, and some cardholders instead of placing their hand signature will put down the words ‘show id’. This further strengthens the safe use of the credit card, as purchases/transactions are prohibited unless there is shown the identity card to the retailer/acquirer.