UTRECHT - In the World Mahjong Championship 2010, ‘Mahjong Competition Rules’ are applied.
These rules were formally established in 1998 by a Chinese state committee, after the government had lifted the ban on mahjong, which dated from 1949, when the People's Republic of China was established. The rules of the ‘new mahjong’ were initially called ‘Chinese Official’, but also ‘International Rules’.

The first world championship where the CO rules were used, was held in Tokyo, Japan, 2002; the second in Chengdu, China, 2007.
The rules are controlled by the Beijing based World Mahjong Organization, which cooperates with the European Mahjong Association, an umbrella where the European national mahjong leagues are associated with.

More information about MCR in Wikipedia
Download the ‘Green Booklet’ with the rules (PDF)
A penalty overview for the WMC2010 and other official tournaments, by EMA (PDF)
Referee manual, by EMA (PDF)