Metadata in .blend, ZTL, OBJ, FBX and etc?

Other than the File | Properties information I can see from Windows Explorer, are there ways to embed and/or read metadata in Bender, ZBrush and allied 3D file formats? I am particularly interested in two things:

  • embedding tags or category information in these files that I can use programmatically to create a database of file information (as I can via jpgs with C),
  • and for security and identification – or at least putting my name and information in a file…

The file specifications for OBJ include the metadata concept, but not for the kinds of user-generated data I was hoping for.

I have not found much more … any input welcome.