Che refers to the diagonal pattern of the "three" pip on the tile. Deng refers to the "one" pip on the tile.
See also: Tien Gow, Pai Gow, Gwat Pai
... 2nd century - 3rd century - 4th century Decades: 190s 200s 210s 220s 230s - 240s - 250s 260s 270s 280s 290s Years: 237 238 239 240 241 - 242 - 243 244 245 246 ...