Regarding the drafting of disclaimers, the Enlarged Board of Appeal stated in G 1/03 and G 2/03 (OJ 2004, 413 and 448) that the disclaimer should not remove more than was necessary to restore novelty or to disclaim subject-matter excluded from patentability for non-technical reasons. The need for a disclaimer was not an opportunity for the applicant to reshape his claims arbitrarily.
In any case, 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.
For more on the above developments, reference is made to G 1/03, points 2.2 and 2.4 of the order and point 3 of the Reasons (OJ 2004, 443 and 445). On the issue of drafting disclaimers, see also G 2/10, point 3.6 of the Reasons (OJ 2012, 396).
T 747/00 relates to the condition set by G 1/03 (point 2.2 of the Reasons) that a disclaimer should not remove more than is necessary either to restore novelty or to disclaim subject-matter excluded from patentability for non-technical reasons. The board concluded that since, in the absence of a novelty-destroying disclosure, the disclaimer removed subject-matter without any need to do so, that disclaimer necessarily removed more than was necessary to restore novelty, which was not allowable (see also T 201/99). In T 1050/99 the board concluded that the disclaimer covered more than was disclosed in the prior art and thus removed from the claim more than was necessary to restore novelty. See also T 285/00 which concerned a disclaimer largely not based on the disclosure of a prior art document cited under Art. 54(3) EPC 1973, thereby rendering the remaining claimed subject-matter more distant from a relevant prior art document cited under Art. 54(2) EPC 1973.
In T 382/07 it was decided that the five disclaimers did not remove more than was necessary.
In T 8/07 the board had to decide on the allowability of a disclaimer under Art. 123(2) EPC. The board observed that G 1/03 stated that a disclaimer may serve exclusively the purpose for which it is intended and nothing more. If a disclaimer has effects which go beyond its purpose, it is or becomes inadmissible. Further, the necessity for a disclaimer is not an opportunity for the applicant to reshape his claims arbitrarily (G 1/03, point 3 of the Reasons). Therefore the disclaimer should not remove more than is necessary to restore novelty or to disclaim subject matter excluded from patentability for non-technical reasons. From that the board found that it could not be derived from the reasoning of G 1/03 that a patent proprietor is permitted a degree of discretion or latitude concerning the "border" within which the disclaimer should be drafted with respect to the subject matter to be excised. On the contrary, the existence of any discretion regarding the extent of the disclaimer as compared to the subject-matter to be excluded would inevitably introduce a degree of arbitrariness in the drafting of the disclaimer. This would conflict with the express findings of G 1/03. It was therefore concluded that in order to comply with the requirements following from G 1/03 with respect to the drafting of disclaimers it was necessary that these be formulated to excise only that subject-matter which could not be claimed. Further the submission of the patent proprietor that it would derive no advantage was not necessarily and inevitably correct since a broad disclaimer, in addition to restoring novelty would have the further effect of "immunising" the subject matter claimed against a potential attack of lack of novelty.
In T 10/01 the scope of the disclaimer was broader than was necessary to restore novelty. The board nevertheless referred to point 3 of the Reasons for G 1/03, saying that it could also be inferred from that decision that a disclaimer that was broader than strictly necessary to restore novelty might be allowed, depending on the circumstances of the case, if that proved necessary to prevent any lack of clarity in the claim that might otherwise result. However, in the case at issue there was no apparent justification for the disclaimer being broader than the disclosure in document (1).
In T 477/09, claim 1 was modified by addition of a negative feature or disclaimer with a view to restoring its novelty over document D1. It was undisputed that there was no basis for the disclaimer in the application as filed. The board observed that two conditions relating to the wording of disclaimers had been established in points 2.2 and 2.4 of the order made in G 1/03 and that those two conditions were equally applicable. The patent proprietor therefore could not be considered to have any room for manoeuvre in wording the disclaimer and thereby defining its scope: to satisfy the conditions set out in G 1/03, a disclaimer could not remove more than was necessary to restore novelty. In the case at hand, the board found that the scope of the disclaimer was greater than the actually novelty-destroying disclosure in D1. This meant that it did not meet the condition in point 2.2 of the order as read in conjunction with point 3 of the Reasons for G 1/03. The disclaimer in auxiliary request IV was therefore not allowable and was refused accordingly (see also point 1.2 "Intermediate generalisation - non-disclosed combinations").
In case T 440/04, the question was whether disclaiming example 1 of C63 was sufficient to restore novelty. Whereas on the one hand a disclaimer should not remove more than was necessary to restore novelty, it cannot, on the other hand, be considered to serve its intended purpose when it excises less than what is necessary to restore novelty. The disclosure in C63 of fibres having compositions and properties as required by the present claims 1 according to all requests was not strictly limited to the fibres described in example 1 of C63. "Cutting out" the latter fibres was thus not sufficient to exclude from the said claims 1 all those fibres disclosed in C63 having a composition and the inherent properties according to said claims. In the present case, the disclaiming of example 1 was thus not sufficient to restore novelty of the claimed subject-matter over C63.
In T 1843/09 (OJ 2013, ***), the opponent argued that the disclaimer contravened Art. 123(2) EPC because the wording of the disclaimer that the claimed film "is other than a film of Comparative Example 4 of EP-A 0546184" did not represent a technical feature. The board did not accept this argument. Although it was true that technical information could not directly be extracted from the wording of the disclaimer in claim 1 as such, it should be noted that the disclaimer did not merely cite a published patent document, but clearly referred to a specific disclosure in D15, namely a single film described in comparative example 4. Table 4 of D15, characterised this film unambiguously by a number of technical features. The skilled person was therefore able to determine simply by reading the comparative example in D15 which technical embodiment should be excluded from the scope of the claim. The disclaimer in claim 1 therefore represented a negative technical feature in the sense of G 1/03.