I am hoping this is just a Finnish naming custom I don't understand, but Elias is listed as "Elias Mattson Humalalampi" in his passport record, and changes his name to "Elias Johnson" after arriving in America, but he is listed here and elsewhere as "Elias Abrahaminpoika Humalalampi" and even more confusing still, his father's name is Aaprami. How should I understand the middle naming custom?