EPO G1/16 – clarifies the standard for assessing the allowability of disclaimers

December 2017

Earlier this week, the EPO Enlarged Board of Appeal (EBA) issued its decision clarifying the circumstances in which disclaimers can be introduced into a patent claim.  Their decision, G1/16, is the third Enlarged Board of Appeal decision on the allowability of disclaimers since 2004 - a reflection of the controversy that this form of amendment has attracted at the European Patent Office.  

A disclaimer is a "negative” feature that excludes subject matter from the scope of a patent claim.  For example, where an invention is defined in terms of a halogen gas, a disclaimer may be used to exclude the possibility of that halogen gas being chlorine (e.g. wherein the halogen is not chlorine).  In contrast to the general rule that amendments must not add new subject matter beyond the scope of an application as originally filed (Article 123(2) EPC), an earlier Enlarged Board of Appeal decision, G1/03, clarified that "undisclosed" disclaimers (i.e. ones that did not have basis in the application as filed) could be used in a limited set of circumstances, namely to restore novelty over earlier-filed but later-published prior European patent applications (Article 54(3) EPC prior art);  accidental anticipations (e.g. prior art from a completely unrelated technical field), or to disclaim subject matter which is excluded from patentability for non-technical reasons. 

This practice appeared to conflict with a later decision by the Enlarged Board, G2/10, which suggested that disclaimers had to conform to the gold standard for assessing added matter.  Specifically, in G2/10, it was held that the subject matter remaining in the claim after the introduction of the disclaimer had to be directly and unambiguously derivable from the application as originally filed, when viewed from the standpoint of a skilled person in the light of his common general knowledge.

This new decision has settled this apparent conflict by clarifying that the “gold” standard does not apply to “undisclosed” disclaimers that meet the requirements of G1/03 above.  Rather, the "gold standard" was the relevant disclosure test for assessing the allowability of a claim amendment by the introduction of a disclosed disclaimer (i.e. one that had basis in the application as originally filed). 

The Enlarged Board also clarified that:

“(t)he introduction of (an undisclosed) disclaimer may not provide a technical contribution to the subject-matter disclosed in the application as filed. In particular, it may not be or become relevant for the assessment of inventive step or for the question of sufficiency of disclosure. The disclaimer may not remove more than necessary either to restore novelty or to disclaim subject-matter excluded from patentability for non-technical reasons.”

Accordingly, the “gold standard” of G2/10 was neither intended nor to be interpreted as a departure from decision G1/03.  Instead, the Enlarged Board held that the principles underlying the “gold standard” were already encompassed by the requirements of G 1/03, since undisclosed disclaimers could not alter the technical teaching of the application as originally filed if the criteria of G1/03 were to be met.

It remains to be seen what impact this decision will have on the practice of using disclaimers at the EPO.  However, the Enlarged Board is convinced that the answers presented in this decision will:

“serve as guidance for a uniform approach to assessing the allowability of a claim amendment by the introduction of an undisclosed disclaimer in… cases before the boards of appeal or before the examining and opposition divisions of the EPO.”

If you have any question on disclaimers at the EPO in light of G1/16, or any other patent matter, then please contact your usual HGF Representative.

This update was prepared by HGF Partner Hsu Min Chung.  If you would like further advice on this or any other matter, please contact Hsu Min. Alternatively, you can contact your usual HGF representative or visit our Contact page to get in touch with your nearest HGF office.