What is a P.O. Box commonly used for in terms of mail?

A P.O. Box is primarily used for receiving mail privately from a post office. This option highlights one of the main advantages of a P.O. Box: it provides a secure and confidential way to receive correspondence without disclosing a physical residential or business address. Individuals and businesses often rent P.O. Boxes to ensure that their incoming mail is kept separate from their home or office address, thereby enhancing privacy and security.

While government documents can be sent to a P.O. Box, this does not capture the broader primary purpose of P.O. Boxes, which is to receive all types of mail privately. Maintaining privacy during an application is certainly a benefit of using a P.O. Box, but it is not the most comprehensive or primary use case. Similarly, sending packages securely is not the main function of a P.O. Box, as it is designed primarily for receiving mail rather than dispatching items.