I'm pretty sure he's talking about an external breather. Do an internet search and you'll see loads of options from homemade to store bought set-ups.
Here's the one I have on my '08 Heritage. It goes down to a catch can not pictured.

Good luck and ride safe!

 

I took both of my tubes out of the air cleaner backing plate and "T" them together. Then route a single hose up to the mainframe and back to the rear and down behind the mid-frame area.
By having the tube go upwards, any oil mist that accumulates gets gravity-fed back into the engine. I never get any oil evidence at the tubes end back by the rear area.
I made two block-off plugs for where the two tubes went through the backing plate. I went further than most would have just to block the two holes. I threaded the holes and used stainless bolts with loc-tite, and cut flush on the inside. I wanted an invisible mod with no chance of the plugs being able to go in or out of the backing plate.
Done this on other bikes of mine in the same manner as well. Hope that helps a little.

My backing plate is aluminum. The one pictured above looks like plastic. May have to come up with other ideas of your own depending on what you have.