Shirt of the X (MIC) gives DR3/whatever (what DR is given is dependant on the shirt). Examples are Shirt of the Moon (DR3/silver), Shirt of the Treant (DR3/slashing, and Shirt of the Inevitable (DR3/chaotic)
Axe/Spear/Hammerblock armor properties give DR5 against one damage type (Bludgeoning, Piercing, or Slashing) (it's overcome by the other two types). Really not worth a +2 bonus, though.
Marshall's Hardy Troops aura gives DRX/- where X is the Major Aura bonus.
The Toughness Draconic Aura gives DRX/Magic where X is the bonus.