The EPO must read every claim with the description and drawings, not only when the claim is unclear

2025-06-18EPO

Decision of the Enlarged Board of Appeal G 1/24 (18 June 2025), Heated aerosol generating article with thermal spreading wrap / Philip Morris Products S.A., on referral from Technical Board of Appeal decision T 439/22

The Enlarged Board answered questions referred from an opposition appeal over Philip Morris Products' European patent No. 3 076 804, a heated aerosol generating article, in which the parties disputed the meaning of the claim term "gathered sheet." The referring board asked whether Article 69 of the European Patent Convention governs claim interpretation when patentability is assessed, whether the description and figures may be consulted generally or only for a claim that is unclear read in isolation, and whether a definition in the description may be disregarded. The order states that "the claims are the starting point and the basis for assessing the patentability of an invention" and that "the description and drawings shall always be consulted to interpret the claims when assessing the patentability of an invention," "and not only if the person skilled in the art finds a claim to be unclear or ambiguous when read in isolation." The Enlarged Board found the case law consulting the description only for unclear claims contrary to Article 69, observed that finding a claim clear is itself an act of interpretation, and declined to have the EPO read claims differently from national courts and the Unified Patent Court. It held Article 84 gives no guidance on interpretation, stated that "the correct response to any unclarity in a claim is amendment," and declared the third question, on definitions, inadmissible.

What it changesAt the EPO the description is now part of every reading of the claim, in examination and in opposition, as it already is in infringement courts in Europe and under Phillips in the United States. For artificial intelligence applications that means the definitions section of the specification decides what "model," "training data," "embedding" or "agent" covers when novelty and inventive step are assessed. A broad definition written to capture design-arounds also captures prior art, and a narrow characterization of the preferred embodiment can narrow a claim the examiner would have allowed. The Enlarged Board left open whether an explicit definition can ever be disregarded, so treat every definition as binding. Before any European filing, reconcile the definitions across the family so one term means one thing, delete boilerplate definitions nobody reviewed, and put any limitation needed to distinguish the art into the claim, because the Enlarged Board named amendment as the cure for unclarity.

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Burbage Law is the practice of Jon Burbage, a registered patent attorney. 342 United States patents have issued from applications he wrote; the full list is on the Patents page. More about Jon Burbage.

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