North Ingria was a short-lived country which existed 1919-1920 between Finland and Russia after the Russian revolution.
Some details on it are here, Dead country stamps and banknotes:
https://www.dcstamps.com/north-ingria-1920/
and here:
https://en.wikipedia.org/wiki/North_Ingria
The language of North Ingria is close to Finnish.
Although the first link states that no banknotes were issued, there were apparently notes created by overprinting Russian notes of the period.
This brings up the question as to whether or not these should be added to numista as North Ingria banknotes.