The mark consists of a three dimensional configuration of an RFID reader comprising a housing having a generally quadrangular front face and a plurality of side surfaces connected to the front face. The front face defines a rounded peripheral edge which transitions into the plurality of side surfaces, and further includes a generally quadrangular groove. The front face additionally includes five short grooves in vertical alignment with each other, a generally quadrangular recess and an indicator light disposed along a common horizontal axis with the uppermost short groove. A pair of long grooves are disposed on opposing ends of the short grooves. Six rounded depressions are formed within the front face and are aligned along a common vertical axis with the indicator light and are horizontally aligned with respective ones of the short and long grooves. The front face additionally includes an offset keypad shown in dotted lines. The matter shown in broken or dotted lines is not part of the mark and serves only to show the position or placement of the mark.