Not sure If thats an AAC rule here in Canada I will have to check that out, our local trials are usually crawling with pups from there last shots up in age.
There for socialization or just to get them used to the trial atmosphere.
I have been taking Storm out since she got her last set of shots. she's hit 4 fullblown trials and been at about 6 fun night's at the club so far and at 8 months old, she's a trial Junkie already, at the agility trial last week they had a fenced practice area ,and an open practice area about 60 yds off the trial field, nobody was using the fenced in area so I asked the organizers if I and my granddaughter Alexis an aspiring JH (10) could take her into the fenced area and do some flatwork and low jumps with her, they said sure no problem, well we had a crowd gathered around watching her work,after about 3 minutes time as she's such a vocal little thing. Needless to say they were somewhat impressed with how well she was working for a 8 month old pup, we got some great feed back too, from some Nationaly Qualified ( Sheltie) compeditors that were on site and saw her work as to how to progress with her too so it worked out great all around.