Just had a look, our van has the sticker as well and I am a gas man! Never noticed it before. Regardless, venting for gas appliances has to be permanent, not something you can open or close but it probably covers them! I would have thought most Jayco's have enough vents in anyway.
Ie: Door vents, Range Hood vent, Bathroom vent, and all the holes that let the dust in and the water leak in
