e) Drafting of disclaimers – clarity 

The Enlarged Board of Appeal stated in G 1/03 and G 2/03 (OJ 2004, 413 and 448) that the requirements of conciseness and clarity of Art. 84 EPC 1973 were also applicable to claims containing disclaimers. This meant that a disclaimer was not allowable if the necessary limitation could be expressed in simpler terms in positive, originally disclosed features in accordance with R. 29(1), first sentence, EPC 1973 (R. 43(1) EPC). In addition, a plurality of disclaimers might lead to a claim drafting which put an unreasonable burden on the public to find out what was protected and what was not protected. A balance had to be struck between the interest of the applicant in obtaining adequate protection and the interest of the public in determining the scope of protection with reasonable effort.

In the interest of transparency of the patent, it should be clear from the specification that there was an undisclosed disclaimer and why it had been introduced. The excluded prior art should be indicated in the description in accordance with R. 27(1)(b) EPC 1973 (R. 42(1)(b) EPC) and the relation between the prior art and the disclaimer should be shown.

The following rulings on the clarity of claims including a disclaimer were handed down after the decisions in G 1/03 and G 2/03:

In T 161/02 the board pointed out that the disclaimer combined features which arose from two different documents of prior art, the combination of these features resulting in a disclaimer that corresponded to neither the disclosure of the first nor that of the second document, and which did not make any technical sense. The board held that such a disclaimer rendered the claim unclear within the meaning of Art. 84 EPC 1973, as it did not allow the public to find out what was protected and what was not protected.

To justify the exclusion expressed by the formulation "non-therapeutic use" at the beginning of the disputed claim, the appellant in T 67/02 had cited G 1/03 and G 2/03 (OJ 2004, 413 and 448), which had ruled that disclaimers were admissible for subject-matter not patentable under Art. 52 to 57 EPC 1973. However, the board found that in the present case it was not possible to identify a clear distinction between cosmetic use and therapeutic treatment. The board therefore took the view that the exclusion rendered the claimed subject-matter unclear.

In the claim at issue in T 201/99 the appellants (patent proprietors) replaced the range of treatment times "1-10 minutes" by "1-6 minutes". They argued that the range of 1 to 6 minutes should be regarded as disclaiming a sub-range of more than 6 to 10, so as to remove the area of overlap between the claimed subject-matter and the prior art. The board, however, emphasised that Enlarged Board of Appeal decisions G 1/03 and G 2/03 (point 3 of the Reasons) explicitly ruled out the possibility of hiding a disclaimer by using an undisclosed positive feature defining the difference between the original claim and the anticipation, since this would affect the transparency of the patent (Art. 84 EPC 1973).

In T 286/06 the board held that it derived from the purpose of Art. 84 EPC 1973 to ensure legal certainty, that the wording of a claim could not be interpreted by taking into consideration the teaching of further publications not referred to explicitly in the original documents of the application as being relevant for the interpretation of terms used in the description or in the claims. This applied also in the case of a disclaimer, as the only justification for its introduction in a claim was to exclude a novelty-destroying disclosure and it did not represent an opportunity for the applicant or patent proprietor to reshape its claims arbitrarily (see G 1/03, OJ 2004, 413). The board evaluated the clarity of claim 1, considering what the skilled person would have understood in reading the claim only, taking into consideration common general knowledge. The board concluded that the wording of claim 1 was unclear.

In T 1695/07, claims 1 to 8 of the main request were found by the board to be directed to a method for treatment of the human body by surgery which is excepted from patentability under Art. 53(c) EPC. Claim 1 of auxiliary request 2 included the feature "wherein the process is not a method for treatment of the human or animal body by surgery". Concerning the admissibility of a disclaimer excluding subject-matter not eligible for patent protection, the board in this case first stressed with reference to G 1/03 (OJ 2004, 413) that the requirements of Art. 84 EPC are also applicable to claims containing disclaimers. A clear delimitation and distinction between excepted surgical applications and possibly allowable non-surgical applications of the claimed process requires that the two methods be distinct, i.e. separable, which means that they must be of a different nature and may be carried out in different ways. In the board's view, it could not be seen how the claimed process would work without the surgical steps involved. The board concluded that the requirement of clarity was not met in the case at issue.

In T 1487/09 the board considered that all the requirements of the EPC had to be considered when examining a disclaimer, in particular those of Art. 84 EPC. The board observed that the uses excluded (namely, uses that "comprise or encompass an invasive step representing a substantial physical intervention on the body of a human or an animal which requires professional medical expertise to be carried out and which entail a substantial health risk even when carried out with the required professional care and expertise") were not explicitly defined, but rather must be derived from a condition which was to be fulfilled. Whether this condition was fulfilled or not would have to be established by the reader of the claim. Leaving room for such an assessment by the reader inevitably introduced uncertainty as to the matter for which protection was sought. Hence a lack of clarity arose, which was in breach of Art. 84 EPC. Further, the fact that the wording chosen for the disclaimer was the same as the one used in decision G 1/07 for describing a surgical method did not mean that the claim fulfilled the clarity requirements of Art. 84 EPC. This had to be handled on a case-by-case basis. A similar situation may occur when a disclaimer aiming at establishing novelty over subject-matter of a conflicting application under Art. 54(3) EPC was to be introduced.

In T 447/10, the board stated that according to the established case law of the boards of appeal, the characterisation of a product in a claim by reference to a trade mark lacked clarity because the product's composition could change over the term of the patent (see T 762/90, T 270/11, T 2030/13). In the case at issue, the disclaimer excluding a composition sold under a trade mark was of an uncertain scope, such that the subject-matter of claim 1 in the requests in question lacked clarity.

In T 2130/11 the board held that the difficulty in formulating an allowable disclaimer could not justify an exception to the application of Art. 84 EPC which was not foreseen in the EPC. The requirements of Art. 84 EPC must therefore apply for a disclaimer as for any other feature of a patent claim. However, the condition that the disclaimer should not remove more than is necessary to restore novelty (G 1/03) should be applied while taking into consideration its purpose, namely that the "necessity for a disclaimer is not an opportunity for the applicant to reshape his claims arbitrarily" (G 1/03). In this respect situations could be foreseen, in which, while fulfilment of the condition taken in a strictly literal way would not be possible, a definition of the disclaimed subject-matter, which satisfied the requirements of Art. 84 EPC and fulfilled the purpose of the condition (i.e. to avoid an arbitrary reshaping of the claims), might be achievable. In other words, a disclaimer removing more than was strictly necessary to restore novelty would not contradict the spirit of G 1/03, if it were required to satisfy Art. 84 EPC and it did not lead to an arbitrary reshaping of the claims. In T 1399/13 the board concurred with the approach taken in T 2130/11.