Mry. refers to the Maury Cérès & Dallay specialized catalog for France. (Please note that Yvert & Tellier numbers are used to 1980) We include the Maury catalog numbers (Mry. numbers) for our customers convenience. This catalogue is considered the finest, most informative French Catalogue ever published! Over 1440 color pages with detailed illustrations of types, plate varieties, retouches and more.