[quote]Speciality = Tactical Marine, Apothecary, Chaplain, Devastator Marine etc

Rank = Where they are in the hierarchy of their parent Chapter I.E. Brother-Sergeant, Captain, Honour Guard, Sanguinary Priest, and so on and so forth.[/quote]

Most of the time though it'll equate to a similar thing, especially with the progression of Scout-Devastator-Assault-Tactical etc. But I see what you mean and will edit accordingly.