OSCE
General Information:
Organization for Security and Cooperation in Europe

Since the early 1990s the Organization for Security and Cooperation in Europe, based in Vienna, has issued registration plates to its vehicles operating in the field,but not in Austria itself. These plates are with black lettering on a white background: OSCE, three numerals and one or two letters denoting the mission.
Plates in my collection:
OSCE - Kosovo
From c.1996
Organisation for Security and Cooperation in Europe / MK = Mission in Kosovo / Main seat in Vienna / Used on vehicles active in problem areas.