During prosecution of a patent application, it is sometimes possible to present evidence to the examiner that a reference cited against the applicant was filed after the applicant conceived of the invention. The process of doing this is sometimes called “swearing behind” the reference. When a reference is successfully sworn behind, it is no longer considered prior art.

Although many supporters of the America Invents Act (S. 23)  have tried to minimize the impact of doing away with “first to invent” by saying that there are only a few hundred cases of patent interferences each year (out of several hundred thousand patents issued), the impact would be far greater because eliminating swearing behind would have a far greater impact. I know that I have many times gotten a patent application allowed by swearing behind a reference; if the new law is passed, many patents that would otherwise be allowed will now be rejected. This is yet another reason to oppose the legislation. The bill was passed by the Senate and heads for the House for a vote. Please call your congressman to voice opposition.