Google 一一一一I'm a bus driver. The X means the route has a different final destination than the usual routing of the normal bus. EG: 12 Blair takes the normal routing to Blair, as the posted schedule would make you expect all 12's would go to Blair in the Eastbound direction. 12X La Cité would not go to Blair, but terminates at La Cité Collégiale on D'en Haag street.”