We’ve released the first version of working draft for the IVOA Provenance Data Model at the IVOA documents page:
Updated versions will be put at the same URL (check the date! The first version is from 21st November 2016).
Want to get your hands on the very latest version?
Check out the volute svn repository! Since it’s not so easy to find what you want there, here’s the path to the Provenance Data Model at volute, and here’s a direct link to the latest development draft [pdf].
We’re happy to receive some feedback on the document via IVOA’s data modelling mailing list email@example.com.