If you stumble upon duplicate or multiple persons or companies in Daylite, you can merge them.
To merge, select all duplicates by clicking and holding down the CMD button (⌘). Then click in the Edit menu and select the entry x summarize persons.... or x summarize companies....
A window opens with a preview of the objects to be merged. By setting the star you can decide which data record is retained and is supplemented by the information from the other data records. For information such as the name, category, etc. that is unique in Daylite, the information of the dataset marked with the star is retained in the summary. The information from the other data records is saved in a note on the data record if different.
Finally, click on the Combine button.