The Rugby Committee has just voted (in a rare show of unanimity) to adopt the silent version of 'yes, nine' for all levels of adult rugby.
The verbal 'yes, nine' will remain in effect for U19/high school and younger.
This is meant to take effect immediately - games played March 1 and after.
For adult matches, a silent acknowledgement to the scrumhalf that the scrum is stable and the ball may be put in. This can be done by touching the scrumhalf or by a signal.
The front-row briefing should include agreeing with the scrumhalves in what way the touching will be accomplished and what the signal will be.
Typically, the touch is either in the middle of the back (between the shoulder blades) or on the shoulder. The signal can be a thumbs-up, a nod, a play-on gesture, but needs to be demonstrated to the scrumhalves before the game.
This decision was reached after input was received from all levels of the game in the USA as to what that community would prefer.
-- Steve Parrill, IRB Trainer, Chairman, SRRA, USA Rugby R & L Training Committee