American mahjong
The American additions
The corner numerals, the wind letters and the jokers that American play added to the Chinese tiles.
What it means
A Chinese set says everything in Chinese. The small Western numeral in the corner of a suited tile and the Latin letter above a wind were added for export in the 1920s, when the game crossed to the United States: Joseph P. Babcock's rules of 1920 and the sets he had made carried both, so a player who read neither script could still follow a hand.
The jokers came later. They entered American play in the 1960s and are a feature of the League's yearly card, which lets a joker stand in a matching group of three or more identical tiles, never singles or pairs. There are 8 of them in a game. Each set here draws a family of ten, and every deal shows eight of them, so a joker is a small surprise; the word JOKER beneath the drawing is locked, in the set's darkest ink.
The index numerals here are drawn from Fraunces, with every digit at the same width so a rack lines up; the Han characters from LXGW WenKai TC Bold. Both faces are published under the SIL Open Font License.
The tiles, one by one
Screen 8 of 9 in What's on the tile.
A historian's review of the history on these screens is pending.