You know, you could probably write an XSD to describe rules for your file system.
That's a cool idea.
“I'm sorry Dave. You can't store that type of file in that location.”
”I'm sorry Dave. You can't name that sub-folder that.” etc.
The file system is such an awfully undervalued and under-utilised chunk of technology. It was a hierarchical database long before XML was...
...and you know, if all the data that was in your files was in XML...