The Substantiation Threshold: T 0241/25 on Intermediate Generalisations
Board 3.2.02 establishes a strict pleading standard for added matter objections. Merely pointing to an embodiment and asserting an intermediate generalisation is legally insufficient without explaining the inextricable link.
Drafting a notice of opposition against a patent derived from a long chain of divisional applications often involves hunting for features extracted from specific embodiments. When you spot one, it is tempting to simply cite the original paragraphs and assert an unallowable intermediate generalisation. However, as Board 3.2.02 makes clear in T 0241/25, merely pointing to the source text is legally insufficient to substantiate the objection.
The substantiation threshold for omitted features
The patent relates to a catheter delivery system. During opposition, the opponent argued that claiming a "pull wire" without the "resilient steerable section" disclosed in the same embodiment constituted an unallowable intermediate generalisation. In the notice of opposition, the opponent simply referenced the relevant paragraphs, stating the term was disclosed "in combination with several other features".
The Board ruled this was not a substantiated objection of added matter. To properly raise the attack, an opponent must (i) identify the features which are impermissibly omitted and (ii) explain why the omission introduces added subject-matter (reasons 2.2.2). Relying on established case law (T 1762/21), the panel stressed that this explanation must demonstrate the omitted features are inextricably linked to the claimed ones. Without this reasoning, the objection is unidentifiable.
Severing the structural link
Despite surviving the pull wire attack, the main request failed on a different added matter issue. Claim 1 defined a flex activating member comprising a rotatable member with an internally threaded surface portion, but stated the flex activating member "also has an externally threaded surface portion".
The earliest application as filed disclosed that the externally threaded portion was located specifically on the rotatable member itself. The Board found the original disclosure inextricably linked the externally threaded portion to the rotatable member (reasons 2.2.1). The proprietor's argument that a technically sensible reading would implicitly place both threads on the rotatable member was rejected; the claim language left open the possibility that the external thread was on a different component.
Contextualising the objective technical problem
The proprietor cured the added matter defect in auxiliary request 1'' by specifying that the rotatable member possessed the externally threaded portion. The opponent then attacked inventive step, arguing the objective technical problem should be framed as a purely mechanical issue: how to determine the extent of actuation of the rotatable member.
The Board rejected this formulation. Because the indicator's movement tracked the actively imparted flex, the problem had to incorporate the clinical reality of the device. The panel formulated the problem as providing feedback on the flexed configuration of the catheter to help a surgeon steer it (reasons 5.3). Since the secondary prior art documents concerned twistable tip catheters with a fixed amount of flex, they offered no solution, and inventive step was acknowledged.
Practical implications
This decision formalises a strict pleading standard for intermediate generalisations. Opponents can no longer rely on a blanket statement that a feature was extracted from a specific embodiment. The notice of opposition must explicitly map out the inextricable link between the claimed feature and the omitted features. If this reasoning is absent, the objection may be deemed unsubstantiated and dismissed as late-filed if detailed only on appeal.
For proprietors drafting claims from description embodiments, the case highlights the danger of structural severing. If a feature is disclosed as being on a specific sub-component, claiming it as part of the broader assembly will almost certainly trigger an Article 100(c) EPC trap.