Art. 88(2), second sentence, EPC provides that, where appropriate, multiple priorities may be claimed for any one claim.
In T 828/93 (see in this chapter II.D.5.2) the board confirmed that, because of the legal situation explained above, the possibility mentioned in Art. 88(2) EPC 1973 of multiple priorities for any one patent claim related only to instances where, unlike in the case at issue, the claim contained alternatives and could therefore be split into several subject-matters. See also G 2/98 below.
In T 620/94 it became apparent that the granted claim 1 covered two alternatives A and B of the invention. Only alternative B was disclosed in the priority document; alternative A was contained only in the subsequent European application. Prior art published during the priority interval rendered obvious alternative A. The patent could thus only be maintained in amended form, i.e. limited to alternative B.
In T 441/93 the European patent related to a process for preparing a strain of the yeast Kluyveromyces, which comprised transforming Kluyveromyces yeast cells with a vector comprising, inter alia, a DNA sequence encoding a polypeptide. The invention disclosed in the priority document was a process for the preparation of new strains of the yeast Kluyveromyces, characterised in that protoplasts of such yeast were mixed with and transformed by vector molecules. The board concluded on the evidence that the references to protoplasts in the priority document were of crucial importance and that no mention had been made in it of the possibility of transforming whole cells. It was decisive what process had been disclosed in the previous application since claim 1 of the subsequent application was directed to a process. In so far as claim 1 covered whole cell transformation, it could only be entitled to the filing date of the European application. The board's conclusion was that the claims could be divided into two groups: Group A, enjoying priority rights from the previous application and comprising claim 1 in so far as directed to a process for the transformation of Kluyveromyces protoplasts, and the related further claims; and Group B, only enjoying the priority of the subsequent European application, and comprising claim 1 in so far as not directed to a process for the transformation of protoplasts, and the related further claims.
In G 2/98 (OJ 2001, 413) the Enlarged Board of Appeal analysed the legislative intention behind Art. 88(2), second sentence, EPC 1973 and concluded that a distinction has to be drawn between the two following cases. The legislator did not want several priorities to be claimable for the "AND" claim (e.g. a claim to features A and B, with the first priority document disclosing claim feature A alone and only the second priority document disclosing claim feature B). With regard to the "OR" claim the Enlarged Board drew the following conclusion from the historical documentation relating to the EPC 1973: where a first priority document disclosed a feature A, and a second priority document disclosed a feature B for use as an alternative to feature A, then a claim to A or B could enjoy the first priority for part A of the claim and the second priority for part B of the claim. It was further suggested that these two priorities might also be claimed for a claim directed to C, if the feature C, either in the form of a generic term or formula, or otherwise, encompassed feature A as well as feature B. The use of a generic term or formula in a claim for which multiple priorities were claimed in accordance with Art. 88(2), second sentence, EPC 1973 was perfectly acceptable under Art. 87(1) and 88(3) EPC 1973, provided that it gave rise to the claiming of a limited number of clearly defined alternative subject-matters.
In T 665/00, the appellant (opponent) had raised an allegation of public prior use within the priority interval and had challenged the validity of the priority claim. According to the board, the subject matter of the alleged prior use was both described in the priority document and fell within the scope of the claims of the disputed patent, but the priority document did not necessarily describe all the subject-matters claimed. The board observed that, under Art. 88(3) EPC 1973, the right of priority covered only those elements of the patent application included in the application from which priority was claimed. Different elements of a patent application could have different priority dates. According to G 2/98 (OJ 2001, 413), the approach of recognising different priority dates also applied to a claim using a generic term or formula, provided that the use of such a term or formula gave rise to the claiming of a limited number of clearly defined alternative subject-matters. For the case in hand, the board concluded that, of the different alternatives contained in claim 10 of the disputed patent (relating to a powder containing hollow microspheres the specific mass of which was described by the generic term "less than 0.1 g/cm3"), the non-compacted powders containing "Expancel DE" microspheres were covered by the claimed date of priority. The claimed prior use, which involved a product containing the same "Expancel DE" microspheres, could therefore not be novelty-destroying. See also T 135/01.
On the other hand, in T 1443/05 (also referred to in this chapter II.D.3.1.7), the board concluded that the generic wording of claim 1 did not reveal any clearly defined alternative subject-matters which could have justified the priority right.
In T 1877/08 the patentee had argued that at least for the overlapping portion of the ranges disclosed respectively in claim 1 of the patent in suit and in the priority document, the subject-matter of claim 1 was entitled to the first priority date. Referring to G 2/98 (OJ 2001, 413), the board held that the claimed amounts represented a continuum of a numerical range of values not corresponding to distinctive alternative embodiments. Consequently, no separable alternative embodiments, i.e. elements in the sense of Art. 88(3) EPC, could be identified within that continuum. Hence, the subject-matter of claim 1 as a whole was not entitled to the claimed priority date.
However, in T 1222/11 the board remarked obiter, in relation to the "OR"-claim situation, that the condition "provided that it gives rise to the claiming of a limited number of clearly defined alternative subject-matters" (see G 2/98 above) should be given a different meaning from that attributed to it in T 1877/08, T 476/09, T 1443/05 and T 1127/00. This condition could not be meant to set out the manner in which the subject-matter of the "OR"-claim must be defined. This would, at least in relation to generic terms, be at variance with the disclosure test based on the principle of an unambiguous and direct disclosure (cf G 3/89, OJ 1993, 117). For the purpose of the assessment required by Art. 88(3) EPC, the board considered that the wording of the above condition referred to the ability to conceptually identify, by comparison of the claimed subject-matter of the "OR"-claim with the disclosure of the multiple priority documents, a limited number of clearly defined alternative subject-matters to which the multiple rights of priority claimed could be attributed or not (cf. examples in the Memorandum drawn up by FICPI (M/48/I, Section C) for the Munich Diplomatic Conference in 1973, as cited in G 2/98).
T 571/10 applied the approach of T 1222/11. The application in suit, which concerned a pharmaceutical composition, and European application D9 shared the same filing date and claimed priority from the same earlier national application. By comparing the generic subject-matter of claim 1 in issue with the priority document, the board identified two clearly defined alternative subject-matters (a) and (b). Only alternative (a) was fully disclosed in the priority document and therefore enjoyed the claimed priority. D9 could belong to the state of the art under Art. 54(3) EPC only in so far as the priority of the application in suit was not validly claimed while the priority of D9 was. For alternative (a) of claim 1, this was not the case, since D9 had no valid earlier effective date. For alternative (b) of claim 1, D9 was state of the art under Art. 54(3) EPC only for the subject-matter for which the priority claimed for D9 was valid, which was that of alternative (a). This subject-matter was not novelty-destroying for the subject-matter of alternative (b) of claim 1, as it had no overlap with the latter.
The decision headnote states: "In a case in which a single priority is claimed for a given application and a number of features of a claim of said application are generalisations of specific features disclosed in the priority document, a partial priority is to be acknowledged, as long as it is possible to conceptually identify, by a comparison of the claimed subject-matter with the disclosure of the priority document, a limited number of clearly defined alternative subject-matters, including among the alternatives the specific embodiments which are directly and unambiguously derivable from the priority document. In order for this condition to be met, it is not necessary that the clearly defined alternative subject-matters are spelt out as such in the application, nor that the word "or" actually occurs. This condition extends to the case of multiple priorities. In that case, a comparison with the disclosure of each of the priority documents is necessary and for each of the clearly defined alternative subject-matters the earliest priority from which the alternative subject-matter is directly and unambiguously derivable is acknowledged."
The patent in suit in T 557/13 was granted on a divisional application. Claim 1 was to the use of a cold flow improver to enhance the lubricity of a fuel oil composition. The opposition division concluded that an intermediate generalisation in granted claim 1 with respect to the disclosure of priority document D16 did not give rise to the claiming of a limited number of clearly defined alternative subject-matters (cf. G 2/98, OJ 2001, 427). Hence, although the patent met the requirements of Art. 76(1) EPC, the subject-matter of claim 1 did not enjoy the priority date of parent application D1. D1 was thus state of the art under Art. 54(3) EPC, and claim 1 lacked novelty in view of the use of the product of example 1 disclosed identically in D16 and D1. In so deciding, the opposition division relied inter alia on T 1496/11 (see Chapter I.C.2.4.2).
The board therefore had to consider issues of partial priority and, if partial priority was to be denied, also whether the parent application D1 could be relevant prior art under Art. 54(3) EPC. The board set out the legal framework and reviewed the jurisprudence concerning partial priority in respect of a generic "OR" claim, which it defined as a claim 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, or otherwise. Such a generic "OR"-claim encompassed, without spelling them out, alternative subject-matters having all the features of the claim. The concrete question to be resolved was whether claim 1 enjoyed partial priority to the extent that the use of the product of example 1 as disclosed in D16 was encompassed by the more generic definition of claim 1, rather than being spelt out in it.
In the light of the differing approaches adopted in the various decisions both before and after G 2/98, the board decided to refer the following questions to the Enlarged Board:
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?
2. If the answer is yes, subject to certain conditions, is the proviso "provided that it gives rise to the claiming of a limited number of clearly defined alternative subject-matters" in point 6.7 of G 2/98 to be taken as the legal test for assessing entitlement to partial priority for a generic "OR"-claim?
3. If the answer to question 2 is yes, how are the criteria "limited number" and "clearly defined alternative subject-matters" to be interpreted and applied?
4. If the answer to question 2 is no, how is entitlement to partial priority to be assessed for a generic "OR"-claim?
Concerning the further issue of whether parent application D1 could be opposed as state of the art under Art. 54(3) EPC to claim 1, the board referred the following question to the Enlarged Board:
5. If an affirmative answer is given to question 1, may subject-matter disclosed in a parent or divisional application of a European patent application be cited as state of the art under Article 54(3) EPC against subject-matter disclosed in the priority document and encompassed as an alternative in a generic "OR"-claim of the said European patent application or of the patent granted thereon?
This referral is now pending as G 1/15.