In its ruling G 1/15, the Enlarged Board of Appeal put an end to a long-standing debate over the question under which circumstances and for which (partial) subject matter a priority claim is effective for a generically defined claim (for instance, containing the feature of a fastening device as a generic term for screws, nails, rivets, etc.). The former “heterogeneous” decisions on this topic have led to considerable legal uncertainty. In individual cases, the submission of a Divisional application had to be deliberately omitted so as not to jeopardise the Applicant’s own parent application through the submission of a Divisional application.  

I. The underlying problem of G 1/15

We shall forego an extensive “derivation” of the legal questions dealt with in G 1/15 at this point and simply explain, using two examples, the extent to which the idea of the “toxic” priority and/or “toxic” Divisional applications can (or could) take effect in practice.

In the following, it will be assumed that a priority registration JP contains a claim 1 (JP) with the feature “screw” and an embodiment with a “screw” is explained in the description. During the priority year, a European patent registration EP1 is submitted with a claim 1 (EP1) that differs from the claim 1 (JP) in that a “fastening device” is named in place of a “screw”. The description in EP1 also contains an embodiment with a “screw”. EP1 claims the priority of JP. Shortly before EP1 is issued (in our case, the EPA had already stated its intention to grant), the patent applicant submits a Divisional application EP2 with a claim 1 (EP2) that corresponds to claim 1 (JP), in other words that contains the feature “screw”.

In the past, this kind of constellation could have been interpreted such that the Divisional application EP2 was deemed to be prior art that was prejudicial to the novelty of claim 1 of EP1 (with the “fastening device”) in accordance with Art. 54 (3) because the priority of JP can be claimed for the disclosed object with the “screw”, and only the priority (according to this theory!) of the registration date of EP1 for claim 1 of EP1 with the “fastening device”. In accordance with the principle that the specific anticipates the general, claim 1 of EP1 would thus have to fall (even though on the verge of being issued).

Ultimately, a “self-collision” would nevertheless have had to be negated in the aforementioned case (even “before G 1/15”), because the claim with the “fastening device” can claim the priority of JP for the subset “screw”, and in this respect, EP2 cannot be prior art that is prejudicial to the novelty for this subset (disclosed in EP2).

The answer to the question as to whether this still holds true if ambiguous terminology is used (in the aforementioned case, for example, if the word screw were to be replaced by “an essentially circular fastening device with a roughly linear, relatively wide slit”) is much more controversial. Opinions were divided on this point, something that ultimately led to the certified question of T 557/13. 

II. The referral and corresponding ruling of the Enlarged Board of Appeal

In T 557/13, the submitting Board of Appeal asked five questions, only the first of which was answered. The gist of this first question was the extent to which the effect of a (partial) priority claim can be restricted by certain criteria (apart from the requirement of the “direct and unambiguous disclosure”) in a so-called “generic OR-claim” (in accordance with the aforementioned example, a claim with a fastening device that can theoretically be broken down into the alternatives “screw” and “fastening device, but not a screw”).

The Enlarged Board of Appeal (basically) answers this question with: no - in the sense that there are no further criteria, except that the object for which a (partial) priority is to be claimed, naturally has to be disclosed. 

III. Practical consequences

G 1/15 implies that a partial priority can also be claimed for subject-matter (or better: partial subject-matter) that may be unclear and/or  not consistent with Art. 84 EPC. For the applicant for European patents, this means that self-collisions hardly appear possible between European patent applications of the same patent family, in particular between a parent application and its Divisional application. We are of the opinion that the risk of such a “self-collision” has at least dropped significantly, even if each case still has to be considered individually. However, in the majority of cases the all-clear will now be able to be given (with reference to G 1/15) when it comes to the question of a self-collision between two European patent applications that claim the same priority.

In practice, this ruling is of great significance above all because the first filing is often - e.g. because it is only submitted as an “emergency application” under an enormous time pressure, or because it originates from a different legal system - still “able to be generalised”. With reference to G 1/15, a generalising subsequent application will now be able to be made in many, formerly critical cases, without having to fear that the generalising subsequent application is “toxic” in the case of a Divisional application.  Notwithstanding the above, G 1/15 has nevertheless (once again!) shown how demanding and complex matters relating to claiming a priority can be. It goes without saying that we will be happy to help you assess any such circumstances.