G 1/93 (OJ 1994, 541) stated that the underlying idea of Art. 123(2) EPC 1973 was clearly that an applicant should not be allowed to improve his position by adding subject-matter not disclosed in the application as filed, which would give him an unwarranted advantage and could be damaging to the legal security of third parties relying on the content of the original application. If, however, an added feature merely excluded protection for part of the subject-matter of the claimed invention as covered by the application as filed, the adding of such a feature could not reasonably be considered to give any unwarranted advantage to the applicant. Nor did it adversely affect the interests of third parties. Therefore, a feature which had not been disclosed in the application as filed but which had been added to the application during examination was not to be considered as subject-matter which extended beyond the content of the application as filed within the meaning of Art. 123(2) EPC 1973, if it merely limited the protection conferred by the patent as granted by excluding protection for part of the subject-matter of the claimed invention as covered by the application as filed, without providing a technical contribution to the subject-matter of the claimed invention (see also T 112/95).

These principles were in general confirmed in G 2/10 (OJ 2012, 376), see also G 2/98 (OJ 2001, 413). Pursuant to G 2/10 it was, however, evident from the context that by introducing the "technical contribution" criterion in G 1/93 the Enlarged Board had not intended to amend the definition concerning when an amendment was allowable under Art. 123(2) EPC generally, but that it only had sought a way of avoiding the potentially fatal consequences of the patentee being caught in the "inescapable trap" between the requirements of Art. 123(2) EPC and Article 123(3) EPC.

The question of whether an added feature made a technical contribution or merely limited the scope of protection was discussed in several decisions.

In T 384/91 date: 1994-09-27 (OJ 1995, 745) it was held that the added feature did make a technical contribution. This decision was based on the following considerations: the example mentioned by the Enlarged Board illustrated a case where the feature was clearly not merely a limitation. However, the borderline beyond which a feature was no longer to be considered as making a technical contribution to the subject-matter of the claimed invention and was merely limiting the protection conferred, was not co-terminous with this example but lay between it and the limit of complete technical irrelevance. According to the board this view was consistent with the fact that the Enlarged Board had rejected relevance as a criterion for novelty and inventive step, which would also have implied a comparison with the cited prior art documents. The board explained that the term "invention" did not necessarily imply the presence of novelty and inventive step, as was apparent from the wording of Art. 52, Art. 54 and Art. 56 EPC 1973. The board concluded that there was no need to take into account the prior art documents, but that the assessment of whether the exception for mere limitations applied in a particular case should depend only on the technical relationship of the added feature to the content of the application as originally filed, as understood by a skilled reader. At the least, a feature went beyond providing a mere limitation not involving a technical contribution to the invention if it interacted with the way in which the other features of the claim solved the technical problem, as it was understood from the application as originally filed.

In case T 64/96, a patent relating to a cover for automobile sun visor mirrors comprising rectangular plates overlapping and connected together in chain-like succession was revoked by the opposition division. The third auxiliary request of claim 1 was amended in that it was included as an additional feature that lugs were "integrally formed in said plates". The board came to the conclusion that applying the criterion, as set out in G 1/93 (OJ 1994, 541) and T 384/91 date: 1994-09-27 (OJ 1995, 745), to the case at issue, it could be seen that the feature in question did indeed make a technical contribution to the subject-matter of the claim since forming the lugs integrally with the plates led to a simpler and cheaper construction of cover which, at least by implication, was the technical problem which the invention set out to solve. Thus the addition of this feature to claim 1 of the third auxiliary request offended against Art. 123(2) EPC 1973.

In T 518/99 the board held that the technical significance of a feature in a claim was not governed by its relevance for the assessment of novelty and inventive step vis-à-vis the available prior art, as had been argued by the appellant, but by its contribution to the technical definition of the claimed subject-matter, to be assessed by the skilled person in the light of the original disclosure. Otherwise, the decision about the technical significance of a feature would be subject to different interpretations dependent on the respectively available prior art. The board also rejected the appellant's argument that the disputed feature was technically meaningless because it was unrelated to the essence of the claimed invention. In this context the board referred to G 2/98 (OJ 2001, 413) where the Enlarged Board had found it problematic to try to distinguish between technical features which were related to the function and effect of an invention and technical features which were not, because there were no clear and objective criteria for making such a distinction, which could thus give rise to arbitrariness. The board came to the conclusion that claim 1 of the main request comprised a technically significant feature which was not disclosed in the application as filed and was therefore not admissible.

In T 1779/09 the board considered that the appellant had found itself exactly in the situation envisaged in decision G 1/93. The board considered that a limiting feature which generally would not be allowable under Art. 123(2) EPC could, under certain conditions, nevertheless be maintained in the claim of an opposed patent in the particular situation addressed in decision G 1/93. It then complied with Art. 123(2) EPC by way of a legal fiction. In the case at issue, the term "only" was introduced during the examination proceedings and successfully objected to under Art. 100(c) EPC in proceedings before the opposition division by the former respondent. Since the board considered the term to be truly limiting, its deletion would extend the protection conferred and thereby infringe Art. 123(3) EPC. However, the board held that the exclusive limitation did not influence the solution of the technical problem as understood from the application as originally filed, and hence provided no technical contribution to the claimed invention (see also T 384/91 date: 1994-09-27). It merely excluded protection of part of the invention described in the application, thus not giving any unwarranted advantage to the applicant.

In T 592/99 the board observed that in the case of a product claim concerning a composition defined by its components and their relative amounts given in terms of ranges, it could not be accepted that such ranges, which constituted essential features, did not provide a technical contribution to the subject-matter of the claimed invention, as suggested by the appellant. Any amendment to the ranges had to have the effect of modifying the claimed subject-matter, and thus also provided a technical contribution. If the newly claimed limited range were allowed even though unsupported, any subsequent selection invention based on the new range would have to be refused as not novel, which would otherwise not necessarily be the case. To allow this would, of course, give an unwarranted advantage to the patentee, contrary to the purpose of Art. 123(2) EPC 1973. In the board's view, that was exactly what was meant in the "typical example" given in point 16 of G 1/93, "where the limiting feature is creating an inventive selection not disclosed in the application as filed or otherwise derivable therefrom". Therefore the new feature constituted added subject-matter.

In T 1004/01 the question that arose before the board was whether or not there was a basis in the application as originally filed for a peel strength "of at least 24 grams" to define the claimed laminate. According to the application as filed, the peel strength of the laminate was defined by an open-ended range as an essential feature of the invention. In the general description and the claims there was no further mention of any preferred peel strength range. According to the board, the peel strength of 24 grams could not be detached from the exemplified laminates to form a basis for a generalised lower limit of the claimed peel strength range without taking into consideration the other particulars closely associated therewith. Furthermore, the board pointed out that the general criteria of G 1/93 (OJ 1994, 541) had to be met, namely that the limitation did not involve a technical contribution to the subject-matter of the claimed invention and did not provide an unwarranted advantage. Since the claimed peel strength led to a technical contribution of the claimed subject-matter, the question whether or not the limiting feature created an inventive selection could be left unanswered.

The invention in T 2230/08 concerned a method of regenerating a catalyst/absorber. The undisclosed modification contained in claim 1 as granted and still present in claim 1 of the auxiliary request would be prejudicial to third parties relying on the invention as described in the application as originally filed, as that undisclosed modification which was technically sensible might possibly be the basis for a valuable invention. Claim 1 of the auxiliary request was not restricted to any specific method which would deprive the definition of the temperature of the regenerating gas of all technical contribution within the context of that claim. In the absence of any additional disclosed restricting feature to that effect, the temperature of the incoming regenerating gas was therefore considered to interact with the remaining features of the claim in such terms that it influenced the solution of the technical problem which could be understood from the application as originally filed. It followed that the condition that missing technical contribution be provided, set out in decision G 1/93 (OJ 1994, 541), was not met in the case at issue.

In T 108/12 the formulation "correspondent A maintaining said first signature private to itself" in claim 1 as granted had been replaced by "correspondent A avoiding transmission of said first signature". The board observed that keeping something private, i.e. secret, involved more than merely not transmitting such information. Claim 1 as granted encompassed realisations where signatures were transmitted, but were maintained private. This was no longer required by the amended claim 1. On the other hand, amended claim 1 encompassed signatures which were not transmitted but were nevertheless made public, which was in contrast to claim 1 as granted. Therefore, the features replaced by the amendment did not merely limit the scope of protection of claim 1, but – in contrast to the requirements set out in decision G 1/93 – had a technical effect and contributed to the limitation of the scope of protection of claim 1. Those features could not be deleted from claim 1 without extending the scope of protection of claim 1 and thus infringing Art. 123(3) EPC.

In T 287/14 the board held that the disclaimer "wherein the composition does not contain a beta-nucleating agent" added to the claim was a feature providing a technical contribution to the claimed subject-matter. The disclaimer, by modifying the technical characteristics of the matrix phase of the polyolefin composition of claim 1, gave the appellant an unwarranted advantage by restricting the claimed subject-matter to a group of polyolefin compositions having specific technical characteristics and properties.