I came across a passing mention of a peculiar way they recycle in Belgium (it's not paywalled as you may think, use Google Scholar). They say they sort out plastic containers, cans, and tetrapaks. But what about paper and glass? They seem to be more important waste categories than tetrapaks. It turned out to be not an easy task to find information about it on the internet (or pictures of their trash bins). How do they recycle in Belgium?
Belgium has had several separate recycling streams for decades; for example paper, glass, textile, electronic devices. However about 10 years ago a new recycling stream called PMD was introduced, which stands for Plastics, Metals and Drink cartons. The efficiency of this waste stream is under debate and recently also changed a bit to include more types of plastic. This is one of the reasons why current research on recycling is focusing primarily on this waste stream. The other waste streams get very little attention because they generally work well (perhaps with the exception of electronics recycling and construction waste).