How exactly does this work? I've not used it in my MASTER database...only in some of the small ones sent to me by cousins. Does EVERYTHING HAVE TO MATCH? What happens if the name and siblings are the same...but the birth date is missing? Or there are two children with same name and one died early? What if there are NO dates or places, but the parents and siblings all match? What if EVERYTHING matches except the name itself...one has a middle name the other doesn't? I am ready to add a 2000 name gedcom to my master database and there are probably 150 duplicates. Is it too dangerous to do a "smart merge" before I go through the ancestors which are thought to be duplicates...the new database has dates/places, middle names, and additional spouses, so I don't want to just delete them. Thanks for your advice! I appreciate it. Patije