Numerous printing varieties are known, including plate flaws, sheet-margin markings and shifted impressions. The 20-fillér denomination is even known with the “HIVATALOS” inscription inverted.
The postal use of official stamps is equally fascinating. Some denominations are extremely rare on genuinely used postal items. Covers are also known bearing official stamps together with definitive or postage-due stamps. There are even examples of official stamps being used as regular postage stamps or postage-due stamps—and vice versa.
