During the occupation period, the M.V.i.R. required postal customers to pay a war tax with each mailing.
The war tax could be paid by the sender by attaching a war tax stamp alongside the normal postage. If the sender failed to pay the war tax, the postal service would attach a war tax stamp and charge the recipient upon delivery.
Unlike normal postage of the M.V.i.R. which were overprints of German issues, the war tax stamps were overprints of Romanian issues.
This is a postage due stamp used for collection of the war tax. It was issued in September 1918.