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Case Law of the Boards of Appeal

 
 
5.3. Unity of single claims defining alternatives ("Markush claims")
The situation involving the so-called "Markush practice" wherein a single claim defines alternatives is also governed by R. 44(1) EPC and R. 13.2 PCT. According to R. 44(2) EPC and R. 13.3 PCT, the determination of whether a group of inventions is so closely linked as to form a single general inventive concept shall be made without regard to whether the inventions are claimed in separate claims, or as alternatives within a single claim (see W 35/91).
In W 3/94 (OJ 1995, 775) the board had to decide whether the ISA had substantiated its findings of non-unity. It approached the issue by referring to Annex B, Part 1(f) of the Administrative Instructions under the PCT, as in force from 1.7.1992 (now Annex B, paragraph (f) of the PCT Administrative Instructions, as in force from 1.7.2008) which is concerned with the special situation of the "Markush practice". According to that section of the PCT Administrative Instructions, the requirement of a technical interrelationship and the same or corresponding special technical features as defined in R. 13.2 PCT shall be considered to be met when the alternatives are of a similar nature. The section then specifies when alternatives are to be regarded as "of a similar nature."
In W 1/94, the EPO acting as ISA had found that the compounds according to the "inventions" it had identified did not have a new structural element. Nevertheless the board concluded that the absence of such an element did not automatically destroy the unity of the invention. On the contrary, it was clear from the PCT Administrative Instructions that a technical relationship must be recognised for a group of alternative chemical compounds, such as all the compounds having a common property or activity, and such a common activity existed in the case in point. The new use could therefore form the general inventive concept linking the subject-matters of the claims in accordance with R. 13.1 PCT and had to be treated as a functional characteristic linking the compounds claimed.
In W 6/95 the board referred to the PCT Administrative Instructions which are binding not only for the ISA but also for the board of appeal acting as the "three-member board" according to R. 40.2(c) PCT (see G 1/89, OJ 1991, 155; in the PCT Regulations, as in force from 1.4.2005 the reference to the "three-member board" has been replaced with that to the "review body"). The board noted that it follows from Annex B, Part 1(f)(i) of the PCT Administrative Instructions (now part of Annex B, paragraph (f) PCT Administrative Instructions, as in force from 1.7.2008), that in order to establish unity of invention "a posteriori", it was not sufficient for all alternatives of chemical compounds covered by a Markush claim to have a common property or activity, i.e. be suitable for solving a common technical problem, because according to item (B)(1) they had, in addition, to have a "significant structural element" in common in order for the alternatives to form unity. The board made it clear that it was, however, not in agreement with the explanation given in Annex B, Part 1(f)(ii) PCT Administrative Instructions to assume that the said "significant structural element" had to be novel per se. Rather, this expression meant that in relation to the said common property or activity there had to be a common part of the chemical structure which distinguished the claimed compounds from known compounds having the same property or activity (see also W 6/97).
In T 169/96 the examining division was of the opinion that in the case before it such a single general inventive concept was not present, since the structural alternatives comprised by formula A, which had a common property, did not share a common significant structural element, and, according to the EPO Guidelines C-III, 7.4a, which referred to the text of R. 30 EPC 1973 (old version as in force until 31.5.1991), a common new use of known and novel chemical compounds was not in itself sufficient to establish a common inventive concept within the meaning of Art. 82 EPC 1973. The board noted that the fact that one claim also comprised a known compound, not covered by another claim 2, was of no relevance to the question of unity, because R. 30(b) EPC 1973 (old version as in force until 31.5.91; also under the version in force thereafter) did not require that there must be a common concept unifying different "means" according to it. In other words, it was not relevant in these circumstances that the three different classes of chemical compounds identified by the examining division comprised completely different chemical structures of a residue. The board observed that the above-mentioned Chapter of the Guidelines, as well as Annex B, Part 1(f) of the PCT Administrative Instructions (this corresponds to Annex B, paragraph (f) of the PCT Administrative Instructions, as in force from 1.7.2008) concerning the examination of unity of invention of so‑called Markush‑type claims rightly stated that the said significant structural element might consist of a combination of individual components linked together. It was not stated there that the combination of individual structural elements had to be novel per se, nor did such a requirement follow from Art. 82 EPC 1973. Rather it followed from that guideline that this expression meant that in relation to the said common property or activity there had to be a common part of the chemical structure which distinguished the claimed compounds from known compounds having the same property or activity. In the present case no state of the art was cited which related to chemical compounds which were known to be useful for the production of polymeric compositions of enhanced oxidative stability. The combination of the peroxide group and the residue "An" which was responsible for conferring the oxidative stability, however, distinguished the compounds of claim 2 from all chemical compounds conventionally used as antioxidants in polymeric compositions, on the one hand, and from all compounds conventionally used as polymerisation initiators, on the other hand.
In W 4/96 (OJ 1997, 552) the board of appeal noted that the requirement of a technical relationship as defined in R. 13.2, first sentence, PCT might be met when all claimed alternatives belong to a class of compounds which might be expected to behave in the same way in the context of the claimed inventions ("Markush claims''). The technical relationship involved those common special technical features that defined a contribution over the state of the art (R. 13.2, second sentence, PCT; see also W 6/96). However, such contribution could not be recognised on the basis of this expectation if members of the class had already been shown in the prior art to behave in the manner disclosed in the application. The board added that if at least one Markush alternative was not novel over the prior art, the question of unity had to be reconsidered by the examiner, i.e. a posteriori (see Annex B, Part l (f)(v) PCT Administrative Instructions in conjunction with PCT Search Guidelines; Annex B, Part I PCT Administrative Instructions has become Annex B of the PCT Administrative Instructions, as in force from 1.7.2008; Part II (examples) can now be found in the PCT International Search and Preliminary Examination Guidelines, as in force from 25.3.2004).
The board also held that an objection of lack of unity could be raised a posteriori with regard to all categories of grouping of alternatives of chemical compounds. An a posteriori assessment of unity had to be made in all circumstances in the same way, since the legal requirement of R. 13 PCT was the same for all cases. Therefore, the a posteriori assessment of unity in cases of a functional relationship within a group of compounds had to be made in a manner corresponding to the assessment in cases of a structural relationship. This was appropriate for compounds related by their structure as well as for compounds related by their function. The structural relationship within the meaning of Annex B, Part l (f)(i)(B)(1) and the relationship within the meaning of Annex B, Part l (f)(i)(B)(2) and (iii) served the same purpose: both tests were intended to show whether the alternative compounds were of a similar nature, as was said in the introductory part of Annex B, Part l (f)(i). These tests were only tools in order to determine whether there was unity of invention as defined in R. 13 PCT.