ACT junior rugby union president Martin Sullivan welcomed Rugby Australia's decision to introduce a weight for age guideline after running a pilot program in the capital's under-13s division last year.

Every eight to 15-year-old player in Australia who falls outside the average height and weight range for their age will be assessed on fitness, experience and maturity to determine what division they should play.

It is hoped the move will give parents comfort when their children are playing rugby union given some develop at different rates.

Only a handful of players were shifted between grades in Canberra last year as part of the program.

Sullivan said the response to the trial was positive and was keen to see the Rugby Australia guidelines as the juniors edge closer to the start of their season in May.

"The trial was quite revealing, there wasn't as many children on the higher or lower end of the spectrum who were too big or too small," Sullivan said.

"It did allow for a couple of boys to go up and a couple to go down just to test the process. If that's what Rugby Australia is going to implement, we look forward to doing that here.

"What we're waiting on is the framework of how we manage that. From the results of the trial, it looks like it will be easy to implement.

"When the children register, their weight and their height will be recorded and they'll be identified as part of the process. The intent then is to have a qualified group, appointed by Rugby Australia, to do the evaluation."

The study last year monitored 134 players from Canberra and took date from 1400 players in Sydney.

It found weight alone was not a strong enough factor to use when deciding which grade a child should play in.

Fitness, experience, height, weight and maturity will be evaluated and an independent coach assessor will make a call on children outside the average zones.

"We've been working with Rugby Australia for many years to hone and improve the process around safety and participation," Sullivan said.

"If the children enjoy the game, they'll be safe and the parents will support it. The more aspects we can put in to make it safe for the children will help junior development and give mum and dad confidence."

Rugby league is being urged to follow the same path as parents grow concerned about long-term effects of concussion and injuries in junior sport.

Rugby Australia also trialled a 'blue card' system in Canberra to identify concussed players in senior competition, implementing a mandatory stand-down period for players who suffer head knocks.

That system will be extended to the rest of Australia this season, with players from the fringes of Super Rugby to 12-year-olds to have a 12-day break enforced after being concussed.

Rugby Australia said match officials would be able to use a blue card to send off a player suspected of suffering concussion.

That will trigger an off-field response that ensures the incident is recorded, mandates the player is assessed by a doctor and prevents their competition return for a stipulated period.

The ruling will apply from March 1 to all competitions in Australia from under 13s to senior players but it won't apply to Super Rugby, which is internationally administered.

Players aged 18 and under cannot return to play until 19 days after all symptoms have cleared. Adult players will be allowed to return one week earlier.

Rugby Australia will educate match officials, medical attendants, coaches and team managers about the signs and symptoms and management of concussion.