"Patent Interference Proceedings Before the USPTO"

2002 – Article
Building and Enforcing Intellectual Property Value,

Patent interference proceedings are a form of highly specialized administrative litigation. They are often referred to as “priority contests,” meaning proceedings designed to decide which party made its invention first. That is what they originally were. However, that terminology is now obsolete. In the great majority of cases, interferences are now functionally oppositions or cancellation proceedings. That is, in most cases the issues that are actually litigated are patentability issues, not priority issues. Specifically, the issues litigated in interferences now are typically patentability over the prior art and adequacy of disclosure.