Germany would continue using it until the German Revolution of 1918–1919, which resulted in the founding of the Weimar Republic.

[4] The Weimar Republic did not use it as a national flag though it did see use within the Reichswehr and by many paramilitary organizations including the Freikorps.

[8] During World War II, German prisoners of war who had defected to the Soviet Union and German exiles in the Soviet Union, mainly the members of the Communist Party of Germany, formed the National Committee for a Free Germany, an anti-fascist military and political organization which sought to overthrow the Nazi regime and aided the Red Army in various ways, including the combat against the Wehrmacht, and adopted the black-white red flag as their symbol and as a flag for a possible democratic German state after the overthrow of Hitler.

The manifesto of the organization included criticisms of the "powerless" Weimar Republic and contrasted it to the future democratic state, a "truly popular" democratic government strong enough to crush the remains of the Nazi regime.

The other reason was that the KPD leaders wanted to reassure its majority that the NKFD was not a Communist outfit but a union with all kind of views opposed to Nazism.