Tuscany's Via Francigena runs from north to south, in the direction of Rome, so all of the signs point in that direction. Along the way you'll come across signs with a range of different symbols and logos, but the official route has its own specific signposts.
Signs hiking path: indicates access to the path
Signs along the route
Signs with the pilgrim and stones along the hiking trails
Stickers on poles, walls, etc. to help the orientation