For which purpose is a Return Receipt (PS 3811) primarily used?

The Return Receipt (PS 3811) is primarily used to confirm delivery of a package. This service provides the sender with proof that the package was delivered, along with the signature of the recipient as evidence. It is especially useful for important or sensitive mailings where the sender requires confirmation that the delivery has occurred. Specifically, this receipt can help track when and where packages are delivered, making it an essential tool for individuals and businesses alike to verify the completion of shipments.

The other options, while related to postal services, do not pertain to the purpose of the Return Receipt. Canceling a mailing request, applying for a refund, and requesting a package hold are separate services that serve different functions in the postal system.