Odd_Hound
Super saiyan 4 is the basically when you perfect your basic saiyan transformstions and from there are the boosts. So you can mix SS4 with Blue for example
I don't know if it was because of that for him, but for example in Portuguese it is written as "Super Saiyajin," so it is abbreviated as SSJ.
Psan:SSJ4??? whats the J for??