Armor enchantments can be applied to ANY item not just armor and shields. The AC enchantments actually take the form appropriate to the item being enchanted. Add an AC enchantment to a nymph cloak and you get a Deflection bonus. Add it to a pair of boots, and you get a Dodge bonus. Add it to an amulet and you get a Natural Armor bonus. The elemental resistance bonuses can also be applied to any item. These enchantments are still restricted by the 3 enchantment limit. These recipes require the Create Magical Arms and Armor Feat.