When you are working in the time period of say, 500 to 1400, and you come across potential duplicates that might need to be merged, make sure to post a link to those profiles in a Project that is active with Curators knowledgeable about the time period. If the duplicate branch does not contain any new profiles, it is typically isolated and marked for deletion.
See the first post about the general purpose of the Project, and then go to the last page to post any new potential duplicates. You only need to post 1 match from each branch.
If you don't know how to link to a profile, just go to the main profile page of that person, and copy the web page address. Paste that address as the link in the Discussion Thread and it will identify the person. Alternatively, when you get a notice of a potential duplicate (or blue box in the Tree view), then compare the profiles side by side, and copy that page to your post. You can look through the discussion to see how people do it. They also are helpful if you run into any issues.
https://www.geni.com/discussions/158450?page=1