A company will incur product repair costs in the future if products that it sells currently under warranty are brought in for repair during the warranty period. The company will also incur bad debts expense in the future if customers who buy on credit currently are unable to pay their accounts. The accounting procedures for these two costs (warranty expense and bad debts expense) are related to the same accounting principle. Identify the principle and explain fully how these costs are related to or guided by that principle.