Following a referral to the EPO's Enlarged Board of Appeal relating to the issue of so-called "poisonous divisionals" (discussed in our previous article), it appears that such problems will no longer trouble applicants.

The issue of “poisonous divisionals” has resulted in such seemingly paradoxical problems as the claim of a parent application being held to lack novelty over an embodiment described in its own divisional application.

Yesterday, the Enlarged Board of Appeal wrote to the President of the EPO enclosing a copy of its order in this decision, and advising that the full reasoned decision (G 1/15) will be issued as soon as possible. However, it seems clear from the wording of the order that the problem of poisonous divisionals, and the related problem of toxic priority, are set to disappear.

In an interlocutory decision (T 0557/13) the Technical Board of Appeal referred five different questions to the Enlarged Board of Appeal. However, in the event, the Enlarged Board of Appeal found it necessary to answer only the first of these questions. In view of the answer to the first question, questions two to five no longer apply.

The first question referred to the Enlarged Board of Appeal was as follows:

1. Where a claim of a European patent application or patent encompasses alternative subject-matters by virtue of one or more generic expressions or otherwise (generic "OR"-claim), may entitlement to partial priority be refused under the EPC for that claim in respect of alternative subject-matter disclosed (in an enabling manner) for the first time, directly, or at least implicitly, and unambiguously, in the priority document?

The order issued by the Enlarged Board of Appeal effectively answers "no" to this question. That is, entitlement to partial priority may not be refused, provided the conditions set out in the question are met.

The order states,

Under the EPC, entitlement to partial priority may not be refused for a claim encompassing alternative subject-matter by virtue of one or more generic expressions or otherwise (generic "OR"-claim) provided that said alternative subject-matter has been disclosed for the first time, directly, or at least implicitly, unambiguously and in an enabling manner in the priority document. No other substantive conditions or limitations apply in this respect.

The wording, "No other substantive conditions or limitations apply in this respect" is significant, as this marks a departure from the earlier Opinion G2/98 of the EPO's Enlarged Board of Appeal, which stated,

The use of a generic term or formula in a claim for which multiple priorities are claimed ... is perfectly acceptable... provided that it gives rise to the claiming of a limited number of clearly defined alternative subject matters.

The requirement for "a limited number of clearly defined alternative subject matters" caused a great deal of confusion, and inconsistency in the case law. It appears that this requirement will no longer apply.

We shall be in a position to advise more fully on these issues once the full reasoned decision becomes available. However, in the meantime the order appears to be good news for patent applicants. Applicants filing a European patent application (or PCT application intended to enter the European regional phase) are likely to be able to broaden the disclosure of the priority application, without the need to worry about the problems of poisonous divisionals or toxic priority.