: This is the file format used by the PS3 to install software, such as demos, DLC, or digital games. In the context of custom firmware, a PKG file allows a user to install a game directly to the console's hard drive without needing the physical disc. The Modern "Undisputed Forever" Project
Installing a .pkg file on 3.55 CFW requires a FAT32-formatted USB drive and the built-in Package Manager.
This process preserves your legal backup rights without resorting to piracy.