English: All the styles of the Balkenkreuz used by the Third Reich's Luftwaffe drawn with the official proportions specified by the Reich Air Ministry just before the outbreak of World War II in 1939. The "low-visibility" version on the left were used late in World War II by the Luftwaffe, using only the "flanks" of the marking shown in white for this regulation example. German armored fighting vehicles (AFVs) during the invasion of Poland (September-October 1939) used a plain white cross, but before the onset of Operation Weserübung (April 1940), the black core cross with white "flanks" that the Luftwaffe used had become the basic German AFV national insignia, as used for the rest of the war (to 1945).