We are all accustomed by now to the very important trick of “aging the preliminary amendment”. When we file a transition application (an application filed on or after March 16, 2013 which is tied to some application filed before that date) the usual mistake is to file the preliminary amendment on filing day. The reason it is usually a mistake is that years later in litigation, the infringer will howl that the preliminary amendment added new matter, and that that new matter had been claimed, and that the “new” law of patentability should have been applied to the case rather than the “old” law of patentability that was actually applied to the case (because you refrained from “checking the box” in the ADS).
So the malpractice-avoiding strategy for many fact patterns is the by now very familiar practice of “aging the preliminary amendment”. We file the transition case, and then wait for midnight to pass in Virginia. Only then do we file the PA. Later the Examiner will determine whether or not the PA contains new matter. If the Examiner enters the amendment, this counts as an express determination by the Examiner that the PA must not have contained new matter. This denies the infringer, in litigation, any opportunity to howl about the case having supposedly been examined using the “wrong” law of patentability.
Which gets us to the latest trap for the unwary.