Jamie,
I second that statement, I teach this stuff every day. More to the point, I have delt with emission controlls for over 30 years.
honestly, it sounds to me as though somewhere you have gotten some information that is incorrect.
as an aside, before there was a pcv system, engines had what was called a road draft tube. basicly this was a tube about an inch in diameter that hung off the side of the engine, ending at about the bottom of the oil pan. oil caps were vented to allow fresh air in and the crankcase gasses vented out the end ot the tube, it took them a while to figure out that all that oil all over the bottom of one's car came from that road draft tube.