Platinum Scissors of Karma

So what can they/can't they do?

Until recently my understanding was that they can make everything untradable tradable, except for reverse/timeless/other 'bind on equip' things. Recently a friend of mine told me that PSoK are like normal SoK, meaning they can't be used on anything unless otherwise stated, and that current untradable items will all stay untradable, except mounts, medals, and whatever else gets the "PSoK can be used on this" tag. Does anyone know the true nature of PSoK?

There are some items, that can only be PSOKed, its just like beign karmable but more expensive and its used often for powerfull items or uber items (epic items as well)