This appeared in Will de Seive's These Card Tricks, 1936, p. 8, under the title “Contact Card,” before being published in Greater Magic, 1938, p. 478.
Daniel Rhod reports that, in the 1800s, card cheats used a coin to emboss a mark on a card. It was described by Augustin Cavaillé in his card sharping treatise, Les filouteries du jeu, 1875, p. 78. The description is quite brief: “La marque à la pièce: Le grec opère une pression sur la carte au moyen d’une pièce d’or ou d’argent à bords dentelés.” (The coin mark: The Greek presses the card with a gold or silver coin with denticulate edges.) The gold or silver coins are believed to have been a twenty-franc Louis d'or and a five-franc piece. The Louis d'or was near the size of a U.S. quarter; five-franc piece was a bit smaller than a U.S. silver dollar. Both coins had the high denticulate rim that Cavaillé specified. This rim would produce a distinct ring when pressed into a card. It is likely that only such a ring, and not a fully embossed disk-shape, was desired for card cheating. This ring could be seen in proper lighting, but its value was more likely that it could be easily felt while dealing, like a punched card. It is also conceivable that the embossed ring in the card was used like a bridge or crimp, for a controlled cut or for nullifying a cut. This use is closer to that of Will de Seive's locator card. Unfortunately, Cavaillé's terse description of the card gives no hint of its use.