A hydraulic control valve can be one type of a variable characteristic (e.g., coil voltage). A visual identification system is provided to permit the visual identification of the specific type of the variable characteristic that the control valve is to assist in the assembly of systems utilizing such control valves. The visual identification system includes first and second indicator bearing first and second indicia, respectively, configured to indicate a first value and a different second value of a variable characteristic, respectively. The first and second indicator members are configured to be separately removably mounted to the control valve via a mechanical connection substantially without adhesive such that the appropriate indicator member can be selected and mounted to the valve depending upon what type of valve it is.