Merchant Ensign of Austria-Hungary from 1786 until 1869 and Naval and War Ensign of Austria-Hungary from 1786 until 1915 (de jure, de facto until 1918)
Own work The underlying design of this naval ensign dates from 1786, at which time it was published (flown publically), and therefore it was published well before January 1, 1928 and meets PD-US-expired. It is also PD-AustrianGov as it was inherited by the various Austrian governments that succeeded the Austro-Hungarian Empire.
PavelD