This blog post is the fourth in the series about CommonsDB. If you don’t know about the project at all, I recommend checking out  the first blog post in the series  which has a video clearly introducing the project. Imagine you come across an image on social media and you realize it would fit very well on Wikimedia Commons. But it has been shared so much that all metadata is lost and you don’t know who created it nor what its copyright status is. But, in this imaginary timeline, you also know that Wikimedia Commons has a connection to CommonsDB which might help you. So you start your upload in the UploadWizard as usual and lo and behold, you get notified that Europeana has this image with a Creative Commons Attribution ShareAlike license, so you can go ahead with the upload. Only a few weeks after  the Northwestern hackathon in Arnhem  we headed to the  Wikimedia Hackathon  in Milan.…