Abstract: A book support of the clip-on type including a label holder having at least one transparent label viewing surface which may releasably engage to the front wall of the book support in covering, spaced relation thereto. In a preferred embodiment of the invention, the label holder includes two planar label viewing surfaces which lie in orthogonally oriented planes. When attached to the front wall of the book support, the label holder and front wall form a substantially triangular transverse cross-section. A label having shelf-identifying indicia printed thereon may be removably inserted between the label holder and the front wall of the book support for viewing through the label holder viewing surfaces. The indicia is printed twice in symmetrical arrangement on the label such that the indicia appearing through the first label viewing surface is the same indicia that appears through the second label viewing surface. As such, the shelf-identifying indicia is displayed about a large viewing angle of at least 180.