A situation where the referee gives minor penalties to both teams on the same play or at the same stoppage.
Unlike most amateur hockey, when teams are skating at 5-on-5 in the National Hockey League - NHL and Coincidental Minors are called, teams will skate 4-on-4. However, any additional Coincidental Minors will not reduce the on-ice strength of the teams.
Also, if there is already a powerplay taking place when Coincidental Minors are called, on-ice strength will remain 5-on-4 and no penalty time is placed on the clock. The players must wait for a stoppage to return to the ice in these cases.
Coincidental Minors often occur around the goal crease after the referee blows the whistle as players come together at the net and push, shove or yap at each other. Referees usually try to not call Coincidental Minors without additional penalties being called because teams will just continue to battle after the whistle since there is no danger of being shorthanded.