Shared Parameters - Revit Upgrade

I understand the intended workflow for shared parameters is to have one file on the network shared among all users. We're in the process of getting Revit 2013 setup. I would think to get all the ID numbers the same, you would want to point 2013 to the same shared parameters file currently in use by 2012, correct? Do they change the formatting of this file periodically? Any problems with adding a shared parameters to this file in a newer version not being visible in previous versions?