In principle, the Patent Application is free to choose the terminology it uses in the patent claim. It is important that the terms used are either clear to the person skilled in the art or that they are explained in the description. However, if neither the description nor the general understanding of the skilled person can provide clarity, the claim is invalid.

The disputed Chinese Utility Model of Bo Wanqing claimed protection for an “anti-magnetic clothing”. The claim read: “Anti-electromagnetic pollution clothing comprising a coat and pants, characterized in that the clothing is provided with metallic wires having high magnetic permeability and no remanence or a metallic net or membrane of metallic powder for shielding”.

Jining Weikei Materials Co. and two other companies filed a cancellation application against this Utility Model with the Patent Office. The competent cancellation chamber granted the application and declared the Utility Model invalid. The term “high magnetic permeability” was unclear, which made the scope of protection ambiguous.

Bo Wanqing’s appeal to the court of first instance was unsuccessful. The Beijing Higher People’s Court also confirmed the nullity.

In the Court’s view, it is difficult for the skilled person to determine the meaning of “high magnetic permeability”. Bo Wanquing has not been able to provide any evidence that there is a reasonably uniform understanding of the meaning and scope of “high magnetic permeability” in the technical field in which the claimed clothing is to be classified.

Note: The requirement of clarity has a good and a bad side. On the one hand, it protects the public from unfair patent claims that can be rubber-stamped by the patent proprietor in his favor in the event of a dispute. On the other hand, it creates opportunities for attack that are sometimes not easy to foresee, even for the serious Application. It is therefore important that applicants exercise self-discipline and critically scrutinize all the terms they use.

Chinese Utility Models are not subject to substantive examination, so that registration was possible despite the lack of clarity. While an unclear Patent Application already fails in the Examination Proceedings, an unclear Utility Model can at least be brought down subsequently through Cancellation Proceedings.