What version document populates the Based On field in Vault PromoMats and Medical?
The field Based On populates always the version of the document from which the copy is made.
If the document the user made a copy from increases the version number, this is not reflected in the version indicated of the document under the field Based On.
By clicking on the document under the field Based On, Vault redirects the user to the version that the field indicates.
Knowledge Base: How Does Make a Copy Work in PromoMats?
Vault Help Documentation: Copying Documents