How does Outlook merge work?

Deduper can merge all types of Outlook duplicates. This is most useful in case of duplicate contacts. Merging works the following way:

Base contact is based on the contact that is left unchecked in the group. Before deleting other contacts Deduper checks if other contacts (that are checked to be removed) has some info that the original does not – such as phone number or address. This info is then merged into original contact and the duplicates deleted. If both contacts have all info, no merging occurs – duplicate is deleted then.