A PKG (Package) file acts as a compressed container that the PS3 operating system reads to install software directly to the internal hard drive.
If you legally own the game and DLC, you can backup your own DLC as PKG using tools like or multiMAN for personal archival use. Ps3 Dlc Pkg Files
: Because PKG files install content directly to the internal dev_hdd0/game A PKG (Package) file acts as a compressed
Just having the files is not enough; the PS3 OS checks for licenses. the PS3 OS checks for licenses.