On the recordApril 17, 1997
We made another change in this. Under prior law, if two people both filed a similar patent, they were on equal terms before the law and had an equal burden in terms of proving who had invented first, not who filed first, which is not relevant. We added to the bill after the bill was filed and added language that says, if we have published and someone files subsequent to our publication, we are no longer on an equal footing. We are now in a super-legal position. The person who filed subsequent to us has the burden of proof. We will indeed, in fact, almost assume that the person copied our patent from the publication. And that is a very important difference. It is true under old law we could file, somebody else could file, we would publish, someone else would file, and we would be at greater risk. We have further strengthened the hand of the person who files and is subject to publication.
Source
govinfo.gov




