I did XSD validator back in 2003 and indeed this blog post gives me familiar vibes. I do believe there has to be some sort of common schema format, but I have

I did XSD validator back in 2003 and indeed this blog post gives me familiar vibes. I do believe there has to be some sort of common schema format, but I have no idea how this problem could be solved cleanly in practice, even after 20 years.