Background

In the now seminal decision G1/24, the Enlarged Board of Appeal held that the claims are the starting point and the basis for assessing the patentability of an invention, but the description and any drawings must always be consulted to interpret the claims for this assessment. This requirement is independent of whether the skilled person finds a claim to be unclear or ambiguous when read in isolation.

However, G1/24 provides no specific guidance on how to use the consultation of the description and drawings. This led to initial speculation that the description and drawings can be consulted and disregarded in some circumstances.

In our related article Claim interpretation - emerging trends on what ‘consulting the description/drawings’ in G 1/24 may mean we discuss some of the many decisions subsequent to G1/24 in which boards have held that consulting the description generally does not mean that a claim can be construed more narrowly than the wording of the claim as understood by the person skilled in the art would allow, such as by implying the presence of additional features which only appear in a specific embodiment in the description.

T439/22 and T1849/23, discussed below, are examples of cases in which boards considered that the description can in fact be used to broaden the meaning of a claim beyond its literal reading, suggesting that diverging branches of case law may be appearing.

T439/22 

G1/24 was the result of a referral from T439/22. Since the referred questions have been answered, the Board of Appeal has now issued its much-awaited decision on T439/22 which concerns an appeal against the Opposition Division’s decision to maintain EP3076804.

The granted claims of EP3076804 related to an article for a “heat not burn” vaping device comprising an aerosol-forming substrate comprising a “gathered sheet” of material (tobacco); the prior art discloses a spirally wound tobacco sheet. At the opposition stage, the patent proprietor argued that if the term “gathered sheet” is assigned its usual meaning in the art then claim 1 is novel. Conversely, the opponent argued that if the term is interpreted in the light of the description, then it would have a broader meaning and claim 1 would lack novelty. The Opposition Division rejected the opposition and held that the term “gathered sheet” had the meaning commonly understood by the skilled person. In particular, it disregarded the broader definition in the description under the principle that recourse to the description for claim interpretation was only justified in exceptional circumstances.

In T439/22, the Board of Appeal considered that to correctly apply the conclusion of G1/24, it is necessary to determine what is meant by the expression “to consult” and its implication on the required interpretation approach. Notably, the board held that in interpreting the language used in a claim, “consulting”, “referring to”, “using” and “taking into account of” the description and figures are synonyms for the act of deriving the necessary information from the patent as a whole to understand what meaning a person skilled in the art would attribute to the terms used in the claim.

The Board of Appeal went on to take the view that claim interpretation is the result of both reading the claims and consulting the description and drawings as a unitary process (a holistic approach). In line with this approach, the board considered that a person skilled in the art reading the claim in the context of the description and figures will try to take a definition found in the description at face value. Further, as long as the definition is technically reasonable and complies with the overall teaching of the claims, description and figures, the skilled person will read terms in the claim in the sense of the definition, taking into account both the broadening and limiting aspects.

The Board of Appeal also highlighted that the fact the patent defines a term indicates that the patent proprietor considered that the term did not have a meaning so commonly accepted and well established that further explanation would be superfluous. The board considered that the definition of the term “gathered” in the specification did not contradict the commonly accepted meaning but rather encompassed it. The board went on to find that the spirally wound tobacco sheet of the prior art was encompassed by the “gathered sheet” of the claims and, thus, the claims lacked novelty.

The patent proprietor had filed a sole auxiliary request in which the contentious paragraph of the description that contained the definition broadening the term “gathered” was deleted; this paragraph additionally referred to the “gathered sheet” being “compressed or constricted substantially transversely to the cylindrical axis of the rod” (a narrowing limitation). The board held that in the absence of the definition, the claims also encompassed aerosol-forming articles which are not rod-shaped and, thus, the scope of protection was extended and therefore the request was not allowable under Article 123(3) EPC.

This decision highlights the importance of accurately defining claim terms in the description since such definitions will be referred to when interpreting the claims, and it may not be possible to simply delete the definition after grant.

T1849/23

T1849/23 concerns EP3166825, the granted claims of which relate to a device and method for detecting and controlling the dangerous swaying of a trailer which uses an angular rate sensor positioned and configured to measure the rate of angular trailer deflection about a hitch pivot point.

The Board of Appeal agreed with the patent proprietor that, when the claim is read in isolation, a literal reading of the claim excluded a simple yaw sensor as the angular rate sensor. However, when the description and drawings are consulted, the board found that the claim must be construed in a broader manner because the only implementation of the sensor in the description, as well as drawings, was a “gyroscope sensor” (a sensor which measures the yaw rate). In view of this broader interpretation, the board held that granted claim 1 lacked novelty over the prior art. Nonetheless, the patent was maintained on the basis of an auxiliary request limited to a method claim.

This decision again highlights the importance of including accurate definitions of key terms in the description as G1/24 continues to generate much debate.

Further referral

As mentioned above, G1/24 was concerned with defining claim terms when assessing the patentability of an invention. Nevertheless, momentum has been gathering in some quarters to determine whether consulting the description and drawings should also be applied to the assessment of added subject-matter, and to what extent. This has culminated in the referral G1/26 from  T873/24 (which concerns EP3587104).

The granted claims in T873/24 relate to pre-coated steel strips and the key issue concerns whether the omission of units from claim 1 adds subject-matter. The patentee argued that, in accordance with G1/24, the description should be consulted when interpreting claims and, thus, the skilled person would clearly understand the claim without the need to recite units in the claim itself. Conversely, the opponent argued that G1/24 does not apply to the assessment of added subject-matter. This is certainly a case to monitor.

Practice points

The scope of claims may not be as clear as it initially appears because the description and drawings can, in principle, lead to a broader or narrower interpretation of otherwise clear claim language. The best way to broaden or narrow a claim, however, remains by amending the claim language and not through reliance on the description.

When drafting patent applications, adding a broader definition of an otherwise well-understood feature in the specification could potentially lead to said feature being interpreted in the broader way, which could have implications for patentability.

In addition, particular attention is required so that specific examples do not inadvertently broaden definitions in the description.

Furthermore, when amending the description, care is required such that any amendments do not unintentionally result in an unallowable broadening of the claim scope which may lead to an inescapable added subject-matter trap post-grant.  

Case details at a glance

Jurisdiction: EPO
Decision level: Enlarged Board of Appeal
Parties: Philip Morris Products SA (applicant) and Yunnan Tobacco International Co Ltd (opponent)
Citation: G1/24
Date: 18 June 2025
Decision: dycip.com/epo-g1-24

Jurisdiction: EPO
Decision level: Technical Board of Appeal  
Parties: Yunnan Tobacco International Co Ltd and Philip Morris Products SA 
Citation: T0439/22
Date: 11 December 2025 
Decision: dycip.com/epo-t0439-22 

Jurisdiction: EPO
Decision level: Technical Board of Appeal   
Parties: Lippert Components Inc and Alois Kober GmbH  
Citation:  T1849/23
Date: 02 September 2025 
Decision: dycip.com/epo-t1849-23