Flag of Siberia (Mannerheim's Finland)

The flag of Siberia has three equal horizontal bands of green, white and green with a quarter black vertical band at the hoist. The flag is based on the Provisional Siberian government created by the white movement.

Origin
The flag traces back to the original flag of the ephemral governemnt for Siberia during the Russian Civil War by the White Movement. This flag consisted of two equal bands of green and white.

Symbolism
There are varying interpretations as to what the colors and bands on the Siberian flag mean. Most popularly, the white color symbolises the white movement, the central position of the white band representing it's significant importance to Siberia's independence. Furthermore, much like interpretations of the Imperial Russian flag, the white is also speculated to represent god. It is sometimes also considered symbolism of the trans-siberian railway, it's route carving straight through Siberia laterally.

The green bands represent Siberia, a vast forest land stretching from west to east. Both bands symbolising it's encapsulating feature of Siberia, everlasting and monumental in size.

Finally the black represents either the Ural mountains or more whimsically, the disconnection with Soviet Russia to the west. This idea can be taken further. Black is usually symbolic of death something very existent in the Ural mountains towards the latter side of the Civil War. Many White fighters died in order to consolidate Siberia's independence.