Exceptionally rare use of this issue on foreign mail...
1944/45 provisional issue for Serbia, photo used as a postcard, franked with 5 occupation Din (first tariff period), sent from Belgrade (10.II.45) to Yambol (ЯМБОЛЬ) Bulgaria (17.II.45), censored by the military censor in Belgrade. Mail to Bulgaria was charged at domestic tariff. Exceptionally rare use of this issue on foreign mail.