I have used Linux since 2002 and KDE since 1 or 2 years futher that. I have registered to this forum 2008. Some years ago I had problems with kaddressbook. There were a bug which crashed kaddressbook. I have not used that program years. A week ago I imported my contacts to Kubuntu 21.10 kaddressbook. It worked ok.

But the classes and sub addressbooks didn't work. And I have over 100 contacts. Now there are no classes. And first name is first in name field. So, I have contacts sorted by first name.

Therefore, I strongly recommend that the names could put in different fields the first name of my family and maybe the middle name separately. Prefixes should also be in your field.

Thanks for KDE. I have been using it for much longer than 10 years!