What exactly is a service bulletin?

I'm assuming it's not the same thing as a recall. But, if a service bulletin is issued, what exactly does that mean as far as Ford's responsibility. And, is there any way to find out what service bulletins have been issued for a 99 Windstar LX? I looked at the list on here but it doesn't make any sense. The one for air conditioning talks about a luggage rack. Most of them are like that.

A service bulletins are basically a problem or maybe problem that a vehicle can have that needs to be fixed but posses no real safety concerns.Often if a customer never mentions any complaints they wont get done,unless it's easy to do.When there is a possibility (even a small one) of injury it becomes a recall.