a) Combination of the preferred narrower range and one of the part-ranges lying within the disclosed overall range 

The board in T 925/98 noted that, according to the respondent, the range 30% to 50% given in claim 1 infringed Art. 123(2) EPC 1973, since such a range was not disclosed in the originally filed documents of the patent in suit, which only disclosed a general range of 30% to 60% and a preferred range of 35% to 50%. The board held, however, that, according to the established case law, in the case of such a disclosure of both a general and a preferred range, a combination of the preferred disclosed narrower range and one of the part-ranges lying within the disclosed overall range on either side of the narrower range was unequivocally derivable from the original disclosure of the patent in suit and thus supported by it (see T 2/81, OJ 1982, 394; T 201/83, OJ 1984, 481; and T 53/82, T 571/89, T 656/92, T 522/96 and T 947/96 all referring to T 2/81). In the case in point, moreover, graphs indicated that the claimed range was in fact the most efficient one. This frequently cited decision and/or its principles were referred to, for example, in T 328/10, T 2001/10, T 227/13, T 223/17, T 516/18; see also T 1107/06.

In T 249/12 the board allowed the amendment to the range of "10-50 mass %", which combined the use of the upper limit of the less preferred broader range (50 mass %) and the lower limit of the most preferred narrower range (10 mass %). Since both end points of the new range were both specifically mentioned in the application as filed, the new range was "unequivocally and immediately apparent to the skilled person" (T 2/81), i.e. the range was directly and unambiguously disclosed in the application as filed. See also T 1143/17 which relates to the combination of the lower end point of a preferred range with the upper end point of a more preferred range.

In T 2514/16, the board observed that it was allowable to combine thresholds from different levels of preference as long as the new range could be regarded as directly and unambiguously disclosed for the skilled person (G 2/10, OJ 2012, 376). This would depend on how the skilled person would construe the amended claim and whether, on the basis of the common general knowledge in the art, they would consider the application to disclose the subject-matter at least implicitly; this would need to be assessed depending on the specific facts of each case. In the case in hand, the disputed amendment had been taken from a passage of the description as originally filed, with the particularly preferred lower value having been combined with the especially preferred higher value. The board found the amendment to be directly and unambiguously derivable from the original application, noting that it amounted to a limitation of a parameter that had been implicitly present in the original claims, not a selection from alternative embodiments set out in the original disclosure.

The board in T 193/17 distinguished the case from T 925/98. It underlined that in T 925/98 the general and the preferred ranges were disclosed in combination, since independent claim 1 as originally filed disclosed a basic range of 30 to 60%, while claim 2 as originally filed, which depended on claim 1, disclosed a preferred range of 35 to 50%. By contrast, in the case underlying T 193/17 the end points of the two ranges claimed (regarding thickness of the surface coating and particle size) were disclosed in four different dependent claims as originally filed, which each depended exclusively on claim°1. Moreover, T 925/98 dealt with the range of a single parameter, whereas present claim 1 related to the introduction of two parameters.

In T 516/18 the application as filed disclosed two alternative values for each one of the upper and lower limits of the range at stake. The board considered that the person skilled in the art was directly and unambiguously provided with the information that any one of the upper and lower limits proposed could be combined in order to select a suitable range, irrespective of the fact that they were presented as "preferable" or "more preferable" values. The board also noted that, in line with established case law (see e.g. T 925/98), when a disclosure of a general and a preferred, narrower range was provided in the originally filed application, a combination of the narrower range with one of the partial ranges lying within the disclosed general range and located on either side of the narrower range would be considered directly and unambiguously derivable from the originally disclosed ranges.