This year’s Six Nations will adopt the 20-minute red cards trialled in the autumn.
For the first time in the Championship, players sent off for technical fouls can be replaced by a team-mate after 20 minutes in a proactive way that penalizes players rather than teams.
However, referees can still award full and permanent red cards for deliberate and dangerous foul play.
Following its successful debut during the Autumn Nations Series, referees will continue to explain any important decisions made during matches to the audience via microphone.
To speed up the game, the sites have 60 seconds after the try to accept conversions, while 30 seconds must be formed for scraps and exits.
The Six Nations will also come into force with a global legal proceeding designed to protect the scrum-half at the heart of rockers, maulers and scrums.
The Six Nations begin with Wales’ trip to France on Friday, January 31. Scotland host Italy and England travel to Ireland the following day.
