I have blogged before about American flags inside of and on the property of churches. Most recently here and here. Below are flags and pennants of the Navy. According to a Navy veteran and LRC reader, "A church pennant may be flown above the American Flag if a church service is done by naval chaplains at sea for personnel of the Navy. After the service is over, the American Flag must again be placed in the prominent position." The legal requirements can be found in this report (see page 660).