What is "tarnschriften"

Tarnschriften or camouflaged publications were a way to avoid censorship in Nazi Germany between 1933 and 1945. Illegal writings were given an innocent looking cover and first and last pages. Kommunistische Partei Deutschlands published about 80% of the camouflaged publications. An estimated 900-1000 publications were issued with up to 40,000 copies printed per title. Most of the publications were written for Germany, but there were also volumes for Spain and Norway, where a speech by Joseph Stalin was given the title Hvordan kan potetene bevares mot frost (How to keep potatoes from frost).