Chapter 13-2: Apposition
When two words, clauses, or phrases stand close together and share the same part of the sentence, they are in apposition and are called appositives.
In fact, an appositive is very much like a subject complement, only without the linking verb:
My brother is a research associate.
My brother the research associate works at a large polling firm.
Jean became a magistrate.
I have never met Jean the magistrate.