Apparatus for changing the display state of a bistable liquid crystal display on a display tag having a plurality of electrical contact pads connected to a corresponding plurality of electrodes in the liquid crystal display includes a body defining a slot for receiving and locating the display tag with respect to the body; a plurality of contact pins located in the body and being mounted for movement into the slot to contact the electrical contact pads of a display tag located in the slot; drive electronics electrically connected to the contact pins for receiving display command signals from an external source and for applying electrical drive signals to the electrodes of the display when the contact pins are in contact with the electrical contact pads; and operator control means for moving the contact pins into electrical contact with the electrical contact pads and causing the drive electronics to apply the electrical drive signals to the contact pins.