Rubbish

In Japan, you have to separate all your rubbish into burnable, non-burnable, and recyclable. Each type of rubbish has a specific day it will be collected on and you can only put it out on the morning of the collection. If you put the wrong type of rubbish out, the binmen won't take it. Instead they will put a big sticker on it reminding you which days are for which rubbish. In the photo, the bag on the right has one of these stickers on it.