I have been hoping this wouldn't come up yet but I see it has. P just might be for Pindar as in title of. Wouldn't this be like their Pope or something? I stopped researching when I got this far to follow Q last Nov. I really wasn't ready to go down this rabbit hole then.
The title, Pindar, is an abbreviated term for "Pinnacle of the Draco", also known as the "Penis of the Dragon"
The true current Pindar is the head of the Rothschild family based in Germany near Frankfurt
Marquis de Libeaux
All this still does not say who the third ruling family is.