What is a "SteamDB Unknown App"?
This app has been deleted or is hidden to the public. There is extremely limited to no information about this app.
We don't even have a name, hence why we are displaying SteamDB Unknown App "AppID".
If you see someone screenshot a page like this and add some information/images on it, it is most likely fake.
Every change is tracked in history, and can be directly linked to.