Jepson claim

A Jepson claim is a method or product claim where one or more limitations are specifically identified as a point of novelty, distinguishable over at least the contents of the preamble. They may read for instance "A system for storing information having (...) wherein the improvement comprises:". This claim’s name is based on a case, Ex parte Jepson.

In a crowded art, a Jepson claim can be useful in calling the patent examiner's attention to a point of novelty of an invention without requiring the applicant to present arguments and possibly amendments to communicate the point of novelty to the examiner. Such arguments and amendments can be damaging in future litigation, for example as outlined in the Festo decision.

On the other hand, the claim style plainly and broadly admits that that subject matter described in the preamble is prior art, thereby facilitating the examiner's (or an accused infringer's) arguments that the improvement is obvious in light of the admitted prior art, as per 35 U.S.C. §103(a). Prosecutors and applicants are hesitant to admit anything as prior art for this reason, and so this claim style is seldom used in modern practice.