Reference Calibration: Because the list of calibrations can grow quite large over the course of time, it is often difficult to find the more-significant calibration definitions embedded as they are in the large list of all available calibration definitions.  For example, the list might contain template calibration definitions in the midst of calibration definitions made from that template, or it might contain a few finalized calibration definitions in the midst of all the interim versions.  Image-Pro allows you to mark such calibration definitions as reference calibrations and then limit the contents of calibration definition list boxes to list only reference calibrations.  Such a list might hide all but the template or finalized calibration definitions.