In accordance with established board case law, the relevant question to be decided in assessing whether an amendment adds subject-matter extending beyond the content of the application as filed or (in the case of divisional applications) the parent application as filed is whether the proposed amendments were directly and unambiguously derivable from the application as filed or from the parent application as filed. The established case law is reviewed in decisions such as T 1206/01, T 731/03, T 1407/06 and T 1772/06. In G 2/10 the board recalled the definition of the "gold standard" (see the beginning of this chapter).
In this introductory section, decision T 404/03 may be cited which draws a distinction between two cases: the removal (or replacement) of a feature and the addition of a feature. In T 404/03 the board considered that the decisions of the boards of appeal describing and using the current palette of "tests" in connection with various types of amendments might lead to some confusion. As far as the disclosure of a group of features was concerned, as distinguished from their scope, the generalisation of a feature in a claim and the isolation of features from embodiments in the description essentially both involved a deletion of a feature, namely the specific feature and the remaining features of the embodiment respectively. The board therefore considered that these cases could be subject to the same criteria as a pure deletion, and hence, in principle, the three point test. Rather than requiring a specific statement or suggestion in the original disclosure, the three point test was more generous to the applicant because it essentially allowed the deletion of a feature if the skilled person realised from the common general knowledge in that field that the feature had nothing to do with the invention. Moreover, in the board's view, the cases of deletion of features and addition of features had to be distinguished with respect to the allowability of amendments under Art. 123(2) EPC 1973, since the former only removed elements that were originally disclosed and hence might be judged by a skilled person to be inessential to the invention, whereas the latter added new elements lacking any basis whatsoever in the original disclosure (recently cited in T 2359/09).
Introductory overview of relatively old decisions concerning the test which is actually to be applied:
Decision T 194/84 (OJ 1990, 59) related to amendments leading to the generalisation of the subject-matter of an application or to the omission of a feature (in this instance, the use in an electrode of a storage battery cell of cellulose fibres in general instead of natural cellulose fibres). The patentee had taken the view that the amendment was admissible because the original application could properly be cited against the novelty of a more generic claim to cellulose fibres. The board took the view that this approach was based on a misapplication of the novelty test. The test for additional subject-matter corresponded to the test for novelty only in so far as both required assessment of whether or not information was directly and unambiguously derivable from that previously presented in the originally filed application or in a prior document respectively. An amendment was not allowable if the resulting change in content of the application, in other words the subject-matter generated by the amendment, was novel when compared with the content of the original application or, looked at another way, if the said change in content would be novelty-destroying for a hypothetical future claim when the original content would not be. It was important that it was the change in content which was tested, i.e. the amended content minus the original content, so that the test was applicable to amendment by generalisation or omission of a feature.
In T 514/88 (OJ 1992, 570) the board took the view that the two tests in relation to the question of broadening of claims before grant by abandoning a feature, i.e. the test for essentiality (or inessentiality) on the one hand and the novelty test on the other, were not mutually contradictory but represented the same principle. In both cases the relevant question was whether or not the amendment was consistent with the original disclosure. This meant direct and unambiguous derivability from and no contradiction of the totality of the original disclosure (same reasoning followed in T 527/88 and T 685/90).
T 118/89 took a reserved attitude to the novelty test, but at the same time emphasised the importance of the above-mentioned key question, in stating that the allowability of amendments during the grant procedure could be determined without reference to the state of the art simply by comparing the protection sought on the basis of the current claims with the disclosure in the application as filed. There was therefore no objective need to carry out new or modified novelty tests. The test for novelty was similar to that for allowability of amendments under Art. 123(2) EPC 1973 only in so far as the former also involved a direct comparison, in this case between the claims and the disclosure in a document or other evidence possibly prejudicial to novelty, i.e. the state of the art.