If you mark two records as not duplicates, because you don't have enough information, maybe just a name but no address/email - you might want to mark them as not duplicates so you can go through your list. But if new information is added to the record later - like address/email, they should pop back into the duplicate search, so you can compare again. OR...you could have an option to 'reset' your duplicate search, to include all 'marked as not duplicates' again