Yes look at the BD Judges Panel booklet or you could ask the organiser of the comp...
If you're thinking with reference to complaining about the judge at the unaff. comp then I wouldn't bother TBH unless she was abusive as I think BD would view it that your friend had done something wrong, albeit unintentionally...
It was the manner in which they pulled her up that is my issue... and then watched someone whalloping their horse with a whip without any remark (and it was not reflected in their marks either
Just be a little bit careful. Even if this person is a listed judge the chances are that all you'll get is a standard letter that says something along the lines 'We are sorry your friend did not enjoy her first competitive experience, however as it was an unaffilliated event we are unable to comment." One lady that I know complained about a listed judge, & all that has happened is that the judge refuses to judge her anymore.