For example, if a game starts off being about federal agents in an X-files sorta vein, but halfway through the campaign, they discover that there's a civilisation underneath the surface of the world, and the rest of the campaign is spent fighting them, not the mudane crimes with a touch of weird they were before.
Myself, as a player, I'd rather be completely surprised by this. Apparently, I'm by no means in the majority of this. And that sort of thing is what I'm referring to when I speak of IC/OOC knowledge.
What closest resembles your views on IC/OOC info?