The trial, which was approved by the IRB Executive Committee, will operate during the November Test period for international matches only and is designed to give greater clarity to what is a busy area of the game for fourth and fifth officials to manage under existing protocols.

All Unions have been informed of the trial.

The revised technical zone protocol will require players entering the field of play as replacements to only do so from the touchline on halfway once the player substituted has left via the touchline, touch in goal line or dead ball line.

The only exception to the protocol is if an injury necessitates the player being escorted from the field of play by medical personnel. In this case, the player entering the field may do so before the injured player has crossed the touchline, touch in goal line or dead ball line.

The protocol also offers a clear reminder of the procedure should a team have more than 15 players on the pitch at any time for whatever reason.

As per current law, the referee will award a penalty kick against the offending team and order the captain to remove the additional player from the field of play.

"The area of substitution management is a critical element of the game for the match official team," said IRB Chairman Bernard Lapasset.

"The modern game includes multiple substitutions and the aim of this protocol trial during the November Tests is to bring greater efficiency to the procedure, making the area better for all involved in the game."

A thorough consultation process involving Unions and match officials will take place after the trial to provide feedback for the IRB Council to consider whether to adopt the trial protocol into the game.

Click here to view the revised technical zone protocol which will be trialled during the November internationals.