3.6. Implicit features

For consideration of implicit features with regard to Novelty, see chapter I.C.4.3 "Taking implicit features into account".

In T 2517/11 the board held that the fact that a technical feature of a known method was "hidden" – i.e. implicit in a prior art document and not identifiable on a mere reading of that document – and could be detected only by way of a mathematical analysis did not mean that it could not be taken into account as a disclosed feature. If an analysis revealed such a "hidden" feature, that showed it was publicly available; whether there had been any objective reason to carry out the analysis was irrelevant (with reference to G 1/92, OJ 1993, 277). This followed from the objective nature of the problem-solution approach developed in the boards' case law, which entailed consideration of all technical features comprised in the closest prior art, regardless of whether they were directly identifiable or hidden, since even hidden features were publicly available.

In T 1779/19 the board, with reference to T 12/81, OJ  1992, 296; T 666/89, OJ 1993, 594; and in particular T 270/97, stated that the key requirement of an implicit disclosure was inevitability. To implicitly anticipate a given product (from a chemical reaction), the prior art document must disclose a reaction carried out under specific conditions which would inevitably lead to the product in question. The board did not contest in the case in hand that ferrous sulphate was oxidised to ferric sulphate in the presence of air. There was however no basis to conclude how far this reaction would go in D5, which did not disclose a reaction but a solution of ferrous sulphate, and there was no information in D5 how this solution was made and how long and under which conditions it should be stored. The presence of ferric sulphate was thus highly likely or even certain, but there was no way to conclude that this presence would go beyond trace levels.

In T 1501/19 the board decided that a particular hypothetical embodiment (a procedure not described) referred to by the opponent was not directly and clearly apparent from the teaching of citation D1, so it could not be taken as a starting point for the assessment of inventive step or for the formulation of the objective technical problem at issue.

In T 674/21 the board held that the fact that D17 might not explicitly disclose or distinguish between tinting systems for interior or exterior use, nor mention the use of non-infrared-absorptive pigments in that context, did not disqualify it as a suitable closest prior art document. Similarly to the claimed subject-matter, D17 disclosed in-store paint tinting systems and the possibility of interior and exterior application was implicit in the use of decorative paint tinting systems mentioned in D17. The relevant field of application in D17 was thus closely related to the claimed subject-matter, and there was no reason to dismiss it as a suitable starting point.