Hi, does the

event

object have a reference page? Can we affect what's included in it? https://developers.suitecommerce.com/section1521059853

Event objects are specific to the method. Some are documented. And what do you mean by 'affect'? Add additional properties?

Yes, I was hoping one of the objects was dependent on Field Sets.

Well it might be. For example, if the event you're listening to as

afterAddLine

then it might return item data defined by a field set.

Thanks, @Steve Goldberg, I'll give it a go.