In February 1897, 800 copies of MiNr. 1-6 were printed specifically for the Universal Postal Union office in Bern, Switzerland. 760 sets were distributed to member countries, 5 to each member nation. The remainder were used by the Reich Post Office for exchange with a Mr. Antoine in Berlin.
These issues differ slightly from the postally-issued MiNr. 1-6 in that they feature a heavier overprint.