The Consumption of Alcohol Is Not Permitted On This Bus

... except by prior written permission.

How the heck does that letter go?
Dear Mr. Bus Driver,I suffer from a medical condition (being Irish/Scottish/Polish/Russian) that means I can't make a long-distance journey by bus or train without getting mildly swallied. Please can I bring a six-pack of Heineken for the journey? I note there is a toilet on the bus, so I  can guarantee I won't need to ask for a pish-stop along the way.Yours drunkenly,A. Passenger