The swallow-tailed state flag of Finland, also called Naval Ensign of Finland. This  flag is used only by the Finnish Defence Forces installations, units, garrisons, and ships. The flag is also the unit Colour of such units that do not have a Colour of their own.
Described in Act on the Finnish flag (380/1978)
Axel Gallén-Kallela, svg format by User:Denelson83