Whereas novelty is not necessary to establish the technical character of an invention, the converse is not true as novelty and inventive step can only be established on the basis of the technical features of the invention. This is in line with the case law of the boards of appeal (T 154/04, OJ 2008, 46).

The Enlarged Board of Appeal held in decision G 2/88 (OJ 1990, 93) that the claims of a European patent should clearly define the technical features of the subject invention and thus its technical subject-matter, in order that the protection conferred by the patent can be determined and a comparison can be made with the state of the art to ensure that the claimed invention is, inter alia, novel. A claimed invention lacks novelty unless it includes at least one essential technical feature which distinguishes it from the state of the art.

In T 154/04 (OJ 2008, 46) the board stated that it is legitimate to have a mix of technical and "non-technical" features appearing in a claim, in which the non-technical features may even form a dominating part of the claimed subject matter. Novelty and inventive step, however, can be based only on technical features, which thus have to be clearly defined in the claim. Non-technical features, to the extent that they do not interact with the technical subject matter of the claim for solving a technical problem, i.e. non-technical features "as such", do not provide a technical contribution to the prior art and are thus ignored in assessing novelty and inventive step.

In T 2050/07 the board confirmed the established case law according to which features that do not contribute to the technical character of an invention and do not interact with the technical subject-matter of the claim for solving a technical problem have to be ignored when assessing inventive step, such features should equally be ignored when assessing novelty. The board therefore examined whether or not the distinguishing features in the case before it made a technical contribution.

In T 2191/13 the board observed that novelty could not be established on the basis of a distinction made only mentally, i.e. derived solely from pre-existing knowledge and not reflected in the technical features of the claimed subject-matter. It cited the Enlarged Board's ruling in G 2/88 that a claimed invention lacked novelty unless it included at least one essential technical feature distinguishing it from the prior art. It followed from that decision that a feature of a merely mental nature could not be a new technical feature for the purposes of Art. 54 EPC and, therefore, that a claim containing only already known technical features could not be considered novel. This approach was also taken in T 959/98, T 553/02 and T 154/04.