Mintmaster’s Mark. The signature, usually the initial, of the chief official of a mint, infrequently found on coins and medals. Such personal signatures were in addition to that of the die engraver, or mintmark (often two such marks would appear on the same coin, rarely three, as this did lead to some confusion). A modern example is the precious metal products of the jewelry firm of Tiffany & Co., where, since 1880, all items were signed with the last initial of the president’s name (M for Edward C. Moore, P for Henry B. Platt, and such). In a way, it meant the president guaranteed the quality of the piece that bore his initial much like that of a mintmaster’s mark.