Armor on the "upper deck sides"

One feature that I need to add to my program is to include the possibility of armor on the "upper deck sides". I've long been aware of this feature in some ships, but I have generally avoided armoring that place in my own designs. What I am seeing is that to account for all the armor weight in the Queen Elizabeth class and similar ships, I need to include the possibility to armor places that I have not previously allowed, including the upper deck side, the forecastle, and an upper armor strake at the ends, above that at the waterline.