With respect to clarity, see also the comments in the introduction to the previous point, entitled "Drafting of disclaimers".
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 - as acknowledged by the appellant - 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 claim 1 at issue required that the claimed composition comprise specified amounts of a bonding inhibitor which was a quaternary ammonium compound, and contained a disclaimer reading: "provided that said bonding inhibitor is not a biodegradable quaternary ammonium compound". The disclaimer had been introduced during opposition proceedings in order to restore novelty over the disclosure of document (1). The original documents of the application did not contain any citation relating to the possible interpretation of which quaternary ammonium compounds had to be considered "biodegradable".
The board held that it derives from the purpose of Art. 84 EPC 1973 to ensure legal certainty, that the wording of a claim cannot 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", i.e. a disclaimer. Concerning the admissibility of a disclaimer excluding subject-matter not eligible for patent protection, the board in this case first stressed that, with reference to G 1/03 (OJ 2004, 413), 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 and that auxiliary request 2 was therefore not allowable.