The Vaurien Class Rules have been updated by World Sailing. The most recent rules and an overview over the changes can be found here.
Summary of changes is:
It is now class-legal to carry a flotation device at the mast head
Cleats on the sails for any leech lines do not count to the overall number of cleats anymore.
You can now use a clew strap around the boom, similar to ILCA class, instead of having a slide in the boom track. But: If you have a mainsail with a bolt rope or slide, it must be inside the boom track.
On top of that, some small editorial changes have been incorporated.