What is lockable steering, and does my Yaris have it?

I am making a cross-country move in a couple of months. I am renting a moving truck from Penske. I would like to also rent a tow dolly to attach to the truck so I can tow my car. I have a bare bones automatic 2007 2-door Yaris (no options). On the Penske website, it says you need to have lockable steering in order to use a tow dolly and to check your owner's manual if you aren't sure if your vehicle has lockable steering. Despite me asking about 20 times, my dealership never sent me the owner's manual. I can't seem to find the answer through other means and I'm not sure what lockable steering is. Please help!