Hello
@BloonCrusher
We do not allow skins that contain offensive figures or refer to controversial topics. WW1 is one of these topics.
I'm not sure what you mean with Austria/Hungary being banned, however, we allow flags of any country on a skin as long as they are not used to refer to war (e.g. soldier skin of a country currently at war).
If you have more questions, feel free to ask away.
Have a nice day,