1918 S.M. STEAMER IV. (torpédodepot), frame censorship mark in violet color on/for letter envelope (!), c.v.. Pithart this color doesn't report, censorship on letter from torpedo boat S.M.Tb 86F, CDS Field Post POLA/ 22.II.18, envelope on reverse unstuck, else preserved, incl. content, c.v.. ca. 3.500CZK