Each QVD contains an XML header which contains metadata about that QVD. It is very common to leverage this to make a QVD Catalog dashboard to provide some overarching insight into all of the QVDs in your environment.
To see, just select a QVD in a folder connection and change the File format from QVD to XML.
One thing to note is that XML is semi-structured. Fields will appear and disappear based on the data available. For example, a QVD header will contain a Tag table if any of the fields are tagged. If none are tagged, it won’t exist for that QVD. So make sure you handle these different edge cases.