The church pennant and the Jewish worship pennant are the only two flags that ever fly above the national ensign. They are hoisted above the ensign, either at the flagstaff (in port) or the gaff (under way) during the conduct of religious services by a naval chaplain aboard ship. This usage is expressly authorized by law. U.S. Army directives also provide for use of this pennant above the ensign during services aboard Army vessels, but the legal authority for this would appear to be questionable. Although these pennants may be flown ashore, they may not be flown above the ensign except aboard ship. The use of a pennant to signal that divine services were in progress aboard ship is traditionally said to date from the Anglo-Dutch wars of the 17th century. The first mention of such a pennant in the U.S. Navy is in a manuscript signal book dated circa 1827. The earliest depiction, from the journal of a midshipman aboard USS Ohio in the early 1840s, looks very much like the pennant used today.