How to decrypt files that need the .rap file

Yeah... Sorry about that.
I placed a small note on the crypto commit, but it wasn't really intuitive for users to go check the comments and notice that .rap files need to be placed under the dev_usb000.
I guess I should add this information to the Wiki.

There are only two ways to decrypt a PSN game (with a local license). One is using your console's ACT.DAT and your IDPS to generate a new RIF key (this method is still not implemented in RPCS3, but it's not used very often) and the other is simply using the RAP file that comes with the game PKG to generate the referred key.

What is needed is a ps3 with a custom firmware?