Flag of Germany
When Heinrich XI, Prince Reuss of Greiz was appointed by Joseph II, Holy Roman Emperor to rule the then-new Principality of Reuss-Greiz on 12 May 1778, the flag adopted by the "Fürstentum Reuß-Greiz" was the first-ever appearance of the black-red-gold tricolour in its modern arrangement in any sovereign state within what today comprises Germany – the Reuss elder line that ruled the principality used a flag whose proportions were close to a "nearly square"-shape 4:5 hoist/fly ratio, instead of the modern German flag's 3:5 figure.
Reichskriegsflagge
Outside of educational, artistic or scientific contexts, selling and showing symbols of Nazi Germany, including the "Reichskriegsfahne", is illegal in Germany according to "Strafgesetzbuch" section 86a. This covers the version used after 1935 with the swastika. However, the original black-white-red tricolour flag used between 1871 and 1919 can be shown depending on circumstances in different states of Germany. Because members of the far right have used the imperial war flag as a symbol, its use is considered to be a "breach of the public order" in seven states, and flags could be confiscated. In the other nine states, any provocative misuse of the flag can be prosecuted as an ("act contrary to order", an administrative offence that can be handled without a court process and that carries only a fine that is not legally considered a punishment).