Hello everyone... I'm Don and I'm a big fan of North American trains. I've just found this forum which will be fantastic to work my way through. I watch a lot of youtube train videos and browse photo collections on flickr and just had a question about placard loads on tank trains. I've noticed a lot of tank cars that aren't displaying placards and had assumed that they might have been empties but I recently read that class 9 shipments don't always require placards, so I'm just wondering if no placard means class 9 or empty please?