It acts as an unlocker for the "bubble" (the app icon) created by the PS2 Classics Placeholder PKG, allowing the system to launch the PS2 emulator. Why is it Necessary?
"Press start, load the disc, here we go again / Memory card full, gotta save my friends / No CD, no DVD, just a raw ISO / OPL booting slow, man, I need a pro / Polygon hands, texture tear / This ain't a game, this is a placeholder here / Drag and drop, FTP, crossbar scroll / Welcome to the Classics, now gimme your soul." Ps2 Classics Placeholder Rap File
Your console must be running either Custom Firmware (CFW) or PS3HEN. It acts as an unlocker for the "bubble"
However, a quirk emerged in the modding scene. When users began dumping their legally purchased PS2 Classics to back them up, they noticed something strange. Unlike PS3 or PSOne titles, the PS2 Classics shared a universal dependency. However, a quirk emerged in the modding scene
If you are using a pre-packaged PKG, the RAP file must be placed in a specific directory on your PS3 to be recognized: /dev_usb000/exdata/ or /dev_hdd0/exdata/
In the PlayStation 3 scene, the is a licensing token used to activate the "PS2 Classics Placeholder" application. This application acts as a shell that allows custom-made PS2 ISOs (converted to .BIN.ENC format) to run on non-backwards compatible PS3 consoles using the internal PS2 software emulator. Purpose of the RAP File