Slitherine

What about the bosnian allied general in the later serbian list?

May I use it with an allied contingent?
( it's specified in the list : "only one allied contingent")

The Bosnian would be an allied contingent and so cannot be used with any other allied contingents as per the list note.

It isn't as clear as most other allies which are included on the commanders section at the top of lists where the notes mention them as contingents, however, I believe that I'm correct.