Apparently Canada used to have a law banning the sale of caffeinated clear sodas. Actually, the Canadian government didn't allow the sale of artificially-added caffeine in any foods. Therefore, only the naturally occurring caffeine in coffee, chocolate, tea, and dark-colored cola-drinks (since the kola plant has caffeine) was legal.
Many clear sodas in the United States don't have caffeine anyway - Sprite, 7-Up, Ginger Ale - so that may not seem that odd. Then you remember the most caffeinated soda is... Mountain Dew, right? Yep, Canadian Mountain Dew = caffeine-free. (!!!)
In 2002, Pepsi Co did come up with a caffeinated version, called "Dew Fuel", just for sale in Canada, but it wasn't sold as soft drink, it was marketed as "health drink". It went out of production in 2007.
Luckily for Canadians, the law changed in 2012, and now natural caffeine can be added to soft drinks, thus restoring Mountain Dew to its intended glory.
So if you were driving through Canada any time before 2012 and grabbed a Mountain Dew through a drive-thru or at a store, you probably didn't know that you weren't getting the caffeine you desired. Maybe all the sugar made up for it?
To read current Canadian guidelines on caffeine: click here!