The collection consists of diaries, documents, a map of the Zmievskiĭ uezd of the Kharkov region, and printed materials. Diaries by Onopko cover the Civil War period from March 13, 1920 to March 25, 1922, and span from his service in the Kharkov area to his emigration to Prague. The diaries also concern Onopko's years in emigration in France from 1930-1944. Documents are mostly from the Civil War period. Printed materials consist of a clipping and printed drawing.