f is Vita version F is PS3 version.
PS3 version of Project Diva got the capital letter cause of the DLC that vita version has.
So Project Diva F(PS3)= Project Diva f(Vita) + DLC
I may try the new ram site, and download more RAM to my Switch. Not sure if ddr3 is the right ram
for it tho. Edit- no it uses floppy Ram, just like @AncientBoi