In Romania, from 1866 to 1884, there was an official militia organization named "Garda Civică" (Civic Guard), with mainly police-type duties during peace time. Each legion of civic guards had its own flag: the Romanian tricolor with the coat of arms of the respective city on yellow and the legion's number in corners. Here is the respective flag of the city of Focşani.
The flag in the Russian book from 1890 is quite peculiar. It represents the county of Giurgiu (which is wrong, as the district was named "Vlaşca" back then) and the coat of arms on the flag is indeed that of the old county. However, the mural crown, an attribute of cities, should not appear above the coat of arms of a county! Also, it should be noted that it was customary in the late half of the XIXth century to represent the coat of arms of the cities or districts on a Romanian tricolor escutcheon: tierced per pale or per fess.
All this makes me conclude that the flag is the product of a confusion.
