Okay, so the civil ensign / merchant flag of Austria-Hungary was the "double flag". But in almost every picture from ww1 you always see the black-yellow habsburg / Cisleithania flag, which seems to have been much more common.
Which was the national/official flag of Austria-Hungary? how much was the "double-flag" even used? Was it flown in ~ww1 era and before? What did non Cisleithania area use as flag?
>>3267099
The official flag was the dual flag but the black and gold still saw use. The black and gold was most likely used in Austria and represented Austria alone while the duality flag was probably more known to foreigners.
http://www.crwflags.com/fotw/flags/ah.html
https://en.wikipedia.org/wiki/Austria-Hungary#Flags_and_heraldry
I found these links