Don't knwo what they are calling it, but I was told in order to get a AAA parking pass, you had to buy either a package or your tickets through AAA.
Just being a AAA member won't allow you to park in the special area.
Also, at some parks, I've heard it's more of a hassle (more out of the way) to park in the AAA lot than just to normally self park.
Since we usually buy annual passes, though, I've never been able to check it out, since I can't get the pass from my local AAA chapter.