A simplified version of the modern flag of the Ostrogozhsk Cossacks, the unofficial symbol of Eastern Sloboda Ukraine.
The upper two stripes are Ukrainian national colors: blue and yellow, which are often interpreted as the sky and wheat fields. The lower black stripe symbolizes fertile black soil (сhernozem) and sadness for the abolition of the Ukrainian Cossackhood.
Own work based on: Східнослобідська геральдика. Незалежний інформаційно-освітній ресурс «Гайдамака»., Расторгуев, Владимир. ОСТРОГОЖСКОЕ КАЗАЧЕСТВО. История Острогожска: интерактивная энциклопедия
UeArtemis