Psmd-usa-cia-rf-ziperto.part2.rar -

This is the file format used for installing games or applications on a Nintendo 3DS system (typically via custom firmware like Luma3DS and the FBI installer).

Indicates the North American region version of the game. PSMD-USA-CIA-RF-Ziperto.part2.rar

There isn't a "deep story" behind the file name itself—it is simply a standard naming convention used in the game pirating/emulation community to catalog files. The "story" within the game, however, follows a human transformed into a Pokémon who joins an Expedition Society to uncover why Pokémon are being turned into stone. This is the file format used for installing