The Roman titles are both an ancillary and a trait.

For example, the ancillary for Africa is "Provinciae Africa Vetus". The trait describes the territory and its people, some history, challenges, etc.

The trait, is either "Proconsul Provinciae" or "Propraetor Provinciae" or "Rector Provinciae" based on what type of general you have there.

The Trait gives bonuses to law or public order or whatnot.