Extraordinarily, excessively ILLEGAL!
As part of my revenue collecting, I have been recently enjoying illegal usages of postage stamps as revenues on documents during the Civil War and Spanish American War periods. I’m up to about 25 documents now, including a few multiples, some combinations of different postage denominations, some with a postage stamp and a revenue, and even one with a demonetized 1851 postage stamp. They are more common than the reverse (revenues illegally used for postage on cover), but that actually…