What's the difference between Automatic A and Automatic B roaming?

I did a search and found some interesting information, but was not able to pinpoint a more direct explaination.

What I have gathered so far is that there are 2 different roaming types, Automatic A and Automatic B. Would this mean, if I selected Auto A I would be using someone's network other than Verizon's (like Cingular's), and if I selected Auto B I would be using some one else's (like T-Moble's)?

Without getting too technical, am I on the right track? If so, how could I tell which carrier is on Auto A and Auto B?

Also, I would assume that when I have my phone set to roam, and I venture out of Verizon's network, I am not being charged for roaming charges when I am not actually talking to someone.

Thanks for your feedback.

I believe the difference has to do with companies that are partners with Verizon versus companies that are not. Or they have agreements to provide extended service for Verizon versus those who do not have said agreements. My 7135 came defaulted to "Auto B", and when I asked Verizon CS about it they told me to leave it that way.

__________________
Michael

My 7135 came defaulted from Verizon to "Auto A" I was told to leave it there by CS unless I left my home area. 3 months later, CS told me that I should now leave it in "Auto B" all of the time, since I have the America's Choice plan.

On a trip to Louisiana recently, I played with both settings, and seen no difference. I'm sure there is a difference somehow, but since CS told be to leave it in the Auto B mode, I do. When I got back home, I called CS just to double check, and they once again, after checking with a tech, told me to leave it in the Auto B mode. I have with no problems.

I see that both of you who have responded to my post are from the middle west or the west coast. Is there anyone from New England or the east coast that knows anything about this?

Maybe I'll send an email to Verizon or call tech support on this one....