I am designing arms for a Roman Catholic priest who, before entering the seminary, was a solider in the US Army. In this capacity he was awarded several awards and decorations, one of them being the Army Achievement Medal. Under §2.2.3 of the Society’s “Guidelines for Heraldic Practice”, it would be appropriate for him to display his Army Achievement Medal below his arms. Would it be appropriate for a priest to do so?
As a priest, no it would not. Papal decrees over the centuries have explicitly forbidden secular honors from being displayed on a cleric’s arms. The most recent was mid/late 1800s. (I had the citations at one time, but nowadays I’ll have to dig them up.) The only things he could display are ecclesiastical military honors (read Order of Malta, Order of the Holy Sepulchre).