A new class in the RIO ontology: "I know" used mainly in combination with the class "Person"
Currently, I maintain information about 1075 people in my graph, most of which I know, and the rest I know "of" since they appeared, often automatically from Readwise import, as authors of books and papers.
As always, the formal statement should read like a natural language one:
[[A]] is a:: [[Person]] [[I know]]