Abstract: A wall and/or projection board which can be used on both sides and can be engaged in a horizontal wall rail. At least a first engagement element is connected to the wall-board element via a vertical pivot-spindle connection. The vertical pivot-spindle connection is designed such that, following disengagement of a second engagement element, the wall-board element can be pivoted through 180° about the vertical pivot-spindle connection retained by the first engagement element and can be engaged in the wall rail on the other side in relation to the first engagement element.