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In a notice on 2 October 2015 the President of the EPO announced that all proceedings before the EPO Examining and Opposition Divisions in which the decision depends entirely on the outcome of G1/15 would be stayed until the decision in G1/15 is issued.

Stay of Proceedings pending the Issuance of the Enlarged Board Decision

Whilst G1/15 is pending before the Enlarged Board, cases under examination or opposition will be stayed where:

  • an invention to which a claim is directed is not novel and/or inventive in the light of the prior art (including applications belonging to the same family, and the application from which priority is claimed), if the claim is not entitled to partial priority;
  • the claim in question encompasses, without spelling them out, alternative embodiments having all the features of the claim (known as a generic “OR”-claim), i.e. is directed to subject-matter defined by one or more generic expressions, such as a chemical formula, a continuous range of numerical values or a functional definition;
  • the priority document discloses only one or more (specific) embodiments covered by the claim in question (i.e. the claim is a generalisation of the disclosure of the priority document), but not the subject-matter of the entire claim itself; and
  • the outcome of the proceedings depends entirely on how the Enlarged Board answers the points of law referred to it.

Whilst this case was referred to the Enlarged Board of Appeal nearly a year ago, we still await with anticipation the Decision regarding how the partial priorities should be treated. We hope that the EPO will soon provide clarification for applicants as to how cases of this sort will be treated to allow them to alter their practices, if necessary, to avoid creating poisonous priorities or toxic divisionals.

When Partial Priorities are an Issue – “Poisonous Priorities” and “Toxic Divisionals”

Partial priority problems generally arise when the subject-matter of a later application is broadened from an earlier application with the same earliest priority date claimed.

For example, a first application is filed with a claim directed to a feature made from copper. In the second filing (for example, a PCT application claiming priority from the first application), the specification is broadened to state that the feature can be made from a metal (rather than just copper). In this case, the feature “metal” is not entitled to priority from the earlier application which only discloses “copper”. The two applications therefore have different priority dates with respect to this feature.

This is not usually a problem if the priority application does not publish. However, if the priority application is not abandoned or allowed to lapse before publication, the priority document becomes state of the art for novelty purposes only (under Art. 54(3) EPC). The priority application therefore anticipates the later filed application, as copper falls within the scope of metal and therefore anticipates a claim to the metal.

Even if the priority application is not allowed to publish, a similar scenario can occur with divisional applications (“toxic divisionals”). If a parent application has a claim directed towards metal and a daughter application has a claim directed towards copper, again, the two applications will have different priority dates with respect to this feature and therefore the application stating copper (which has an earlier priority date) will anticipate the application which claims “metal”.

Under Art. 88 (2) EPC, a claim may have multiple priority dates. Therefore, where a priority document discloses one alternative and the later filed document discloses a second alternative, it is clear that the two alternatives have two different priority dates.

The issue of where a later application discloses a genus that encompasses a single species of that genus which was disclosed in the earlier application was addressed in G2/98. In this decision, the Enlarged Board decided that a generic claim could be entitled to multiple priorities where “it gives rise to the claiming of a limited number of clearly defined alternative subject-matters”. However, how many alternatives are a limited number?

In T557/13, 5 questions regarding this point and the topic of partial priorities were referred to the Enlarged Board of Appeal. These issues will be decided in G1/15.


Our articles are for general information only. They should not be considered specific legal advice, which is available upon request. All information in our articles is considered to be accurate at the date of publishing.


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