When you are using the result code option (in Geocode Options dialog box) MapInfo Pro will generate a code for each record. These codes indicate the steps MapInfo Pro took to geocode the record, whether or not the geocoding was successful, and whether or not the match was exact. You can use return codes to diagnose MapInfo Pro's geocoding performance. It will help you spot "false positives" resulting from using various geocoding options and to analyze why some records have not been geocoded.