
Special Beginners is for an exhibitor/dog that hasn't won a CC. We only have one breed open show so I enter this class :) There isn't an age limit on it, but you can win out of it. At the club champ show I enter the post-grad as we haven't won out of it yet, but too old for junior :)
Never herd of the pet one though!
I think it just gives more classes :D