An ink cartridge, comprising a rectangular ink reservoir having a front, a back and a bottom, the front and the back both intersecting the bottom; an ink supply port formed in the bottom, the ink supply port having an ink supply port axis; an identification block disposed on the back and having a pair of parallel sides, a face lying in a plane parallel to the ink supply port axis, the parallel sides being perpendicular to the face, a plurality of electrical contacts lying on the face, and at least one projection having a tip and extending outward from the identification block away from the back toward the face, the tip of the projection being disposed further from the back than the face. |