Dominoes 49 glyphs, the same combinations vertically for another 49, and also a horizontal and a vertical "back" for a total of 100 glyphs. In this arrangement, both orientations are present: horizontally both tiles [1|6] and [6|1] exist, while a regular game set only has one such tile. The Unicode range for dominoes is U+1F030–U+1F09F. The naming pattern in Unicode is, by example, . Few fonts are known to support these glyphs. While the complete domino set has only 28 tiles, for printing layout reasons, the Unicode set needs both horizontal and vertical forms for each tile, plus the 01-03 (plain)
Dominoes double-15, and double-18. Larger sets such as double-21 can theoretically exist, but are rarely seen in retail stores, as identifying the number of pips on each domino becomes difficult, and a double-21 set would have 253 pieces, far more than is normally necessary for most domino games even with eight players. The oldest confirmed written mention of dominoes in China comes from the "Former Events in Wulin" (i.e., the capital Hangzhou) written by the Yuan Dynasty (1271–1368) author Zhou Mi (1232–1298), who listed "pupai" (gambling plaques or dominoes), as well as dice as items sold by peddlers during the reign