There is a big important street in Toronto that has a (narrow) reserved curb lane: at rush hour, only buses and high-occupancy vehicles are supposed to use it. Or maybe only buses and taxis, I forget. The point is that unlike most other reserved curb lanes in the city, this one does not include bicycles. However, bicycles are not legally prohibited from using that road. The city probably meant to discourage cyclists from using this road with such a signage, but they did not outright prohibit it. So I wonder where they expect cyclists to ride on that road. More importantly, I wonder where YOU would ride on that road.
I myself always ride in the right-hand lane, though not in the centre as I otherwise might. I do ride far enough left though to discourage buzzing.