The mark consists of The mark consists of a three-dimensional configuration of a writing instrument barrel and cap. The barrel is a cylindrical shape comprising about one third of the length of the writing instrument. The cap starts as a cylindrical shape at its distal end, tapers to an octagonal shape which extends about two-thirds the length of the cap, and then tapers to a cylindrical shape at its proximal end. The end of the cap is a rounded surface. The portions of the barrel shown in broken lines are intended solely to indicate the positioning of the mark and are not part of the mark.