André is the IT security manager at ThorTeaches.com, where we handle sensitive customer data, such as financial and personal information. One of his employees has recently raised a concern that data labeling within the company is not consistent and could potentially lead to data breaches. As a result, he has asked to implement a new data labeling system to ensure the security and protection of ThorTeaches.com's data. Which of the following is the most effective data labeling practice for ensuring the security and protection of the company's data?