original: The NHL instituted the icing rule on March 13, 1939.
simplifications: The NHL added the icing rule on March 13, 1939. The NHL started using the icing rule in 1939. The NHL's icing rule started in 1939. The NHL made the icing rule in 1939. The NHL started using the icing rule on March 13, 1939. The NHL made the icing rule on March 13, 1939. The icing rule was placed into effect by the NHL on March 13, 1999. The NHL put the icing rule in place on March 13, 1939. Icing started in the NHL on 3/13/1939. On March 13, 1939, the NHL instituted the icing rule.