From Ian Cook, according to Ian Cook
Yep. Posted about it here back in 2008
and here
http://www.rugbyrefs.com/archive/index.php/t-7496.html?
10th post from the top
It was in reply to YOUR statement
I've never been a fan of a team being rewarded for intentionally putting the ball out of play.
Although I have to admit to pinching the idea off Rugby League in the first place,,
[LAWS]
Section 13: Penalty Kick
NOTES:
Differential Penalty. In respect of misconduct at the scrum other than foul play or the use of offensive or obscene language a Referee shall award a differential penalty which differs only from a penalty kick in that a goal cannot be scored from it. The differential
penalty applies to all players, even those outside the scrum, who should be penalised where they offend. A full penalty is
awarded for an offence which occurs before the scrum is properly formed.[/LAWS]
[LAWS]
Section 17: Referee Signals
Differential Penalty. Extend the arm as for an ordinary penalty then move the arm to the upright position. Perform this action twice with the whole movement being continuous and decisive.[/LAWS]