The dwarven gods true names can only be known by dwarves. They are referred to by nicknames in the presence of non-dwarves. I.E. Gudurran( Allfather) Baenna ( Hearthmother) Dudrak ( Ore), etc. No torture or magic or direct intent can reveal their true names to non-dwrves.
Orcs record their deeds through symbolic mutilation, scarring and tattoo. Perhaps creating the medium of skin as art, which humans followed later. Perhaps tattoos remind the elves of orcs and make them angry...