European Patent Office – Enlarged Board of Appeal
round-up

“Far-fetched and utterly implausible”

Novelty: G 1/23 – “Solar
Cell”

On 2nd July 2025 the Enlarged Board of Appeal (EBA) of the
European Patent Office (EPO) released its decision in referral G
1/23, in which it had to consider the prior art effect of putting a
complex nonreproducible product on the market. According to earlier
EBA decision G 1/92, the chemical composition of a product is state
of the art when the product as such is available to the public and
can be “analysed and reproduced” by the skilled person,
irrespective of whether or not particular reasons can be identified
for analysing the composition.

The case arose from opposition/appeal proceedings (appeal number
T0438/19) in connection with European patent number 2626911. The
opposition was rejected by the Opposition Division, which found
that the invention involved an inventive step, against which
finding the opponent appealed. The closest prior art was the
commercially available product “ENGAGE® 8400”, a
complex polymer. The method for manufacturing the product exactly
was not in the public domain, and its exact reproduction is not
straightforward, even if the material, i.e. the final product
itself, is available to the skilled person for analysis. The
opponent argued that the skilled person could make a product
sufficiently similar to ENGAGE® 8400, and an exact reproduction
(following G 1/92) is not required. The proprietor argued that this
product is not prior art because its composition/internal structure
cannot be reproduced (following G 1/92).

The EBA was thus asked to answer 1) whether a product put on the
market before the filing date of a European patent application can
be excluded from the state of the art under Article 54(2) EPC
solely because its composition or internal structure could not be
analysed and reproduced by the skilled person before the filing
date. If the answer to this question is “No”, then the
EBA was also asked 2) whether any technical information about such
a product that was made publicly available before the filing date
forms part of the state of the art, regardless of whether the
skilled person could analyse and reproduce the product and its
composition or internal structure. (There was also a third question
referred, but this was moot).

The EBA held that:


A product made available to the public (e.g., by being put on
the market) cannot be excluded from the state of
the art simply because its composition or internal structure could
not be analysed and reproduced by the skilled person before the
relevant date (i.e. the answer to Question 1) is “no, it
isn’t excluded”).

Any technical information about such a product that was made
publicly available before the filing date forms part of the
state of the art, regardless of whether the skilled person
could analyse and reproduce the product and its composition or
internal structure (i.e. the answer to Question 2) is “yes, it
does form part of the prior art”).

The EBA found that answering “yes” to question 1)
would mean that the product “simply does not exist” for a
skilled person, which “directly contradicts everyday
experience”, and “is clearly far-fetched and utterly
implausible, manifestly contradicting notorious facts”. This
leads to “an absurd result and cannot hold”. The EBA thus
found that the requirement for the product to be
“reproducible” from G 1/92 must include being able to
obtain the product from the market, to avoid the logical conclusion
that otherwise “no material in the physical world would belong
to the state of the art”.

Thus, it is questionable whether this decision does anything
other than clarify what most (sensible) patentees were already
practicing, i.e. if you wish to seek patent protection for a new
chemical product, then file your patent application prior to
offering the product for public sale.

“Gather round the campfire, everybody – we’re
going to read a patent specification”

Claim interpretation: G 1/24 – “Heated
Aerosol”

On 18th June 2025, the EBA issued its decision in case G 1/24,
in which it needed to consider questions relating to the use of the
description and drawings of a patent specification when
interpreting the claims. The answers to these questions are
fundamental to the assessment of whether an invention is
patentable, with claim interpretation central to a determination as
to whether a prior disclosure is inside or outside the scope of the
claims.

The questions are set out in more detail below, and the response
of the EBA is expressed in decision G 1/24. In summ

“The claims are the starting point and the basis for
assessing the patentability of an invention under Articles 52 to 57
EPC. The description and drawings shall always be consulted to
interpret the claims when assessing the patentability of an
invention under Articles 52 to 57 EPC, and not only if the person
skilled in the art finds a claim to be unclear or ambiguous when
read in isolation”.

This will generally be seen as a simple and logical position for
the EPO to take and addresses some perceived inconsistencies in
prior case law from the EPO’s Technical Boards of Appeal.
Encouragingly, the EBA’s decision is (deliberately) consistent
with the positions of both national courts and the Unified Patents
Court, in which litigation of patents granted by the EPO may take
place.

Background

There are many cases in which the patent drafter has a
particular intention in mind when using specific claim language to
cover an invention. The selected terminology may be the best way to
express the invention concisely, but other literal interpretations
of that terminology may also exist in different contexts that are
further removed from the invention. In such cases, the description
and drawings are typically used by the drafter to provide guidance
as to the meaning which is intended in a particular case.

There are also situations in which selected terminology may have
a more established meaning in a technical field, with fewer
alternative interpretations generally available. Nevertheless, the
drafter may wish to deviate from an established meaning in a
particular patent application by providing a particular definition
in the description and drawings which they intend to be used to
interpret the claims. This situation is the basis on which a
referral was made to the Enlarged Board of Appeal.

The Appeal

The Patent at issue in this litigation was European Patent EP
3076804 (Philip Morris Products S.A.), relating to a vaping device.
The claims as granted specify that an ‘aerosol-forming
substrate comprises a gathered sheet of aerosol-forming material
circumscribed by a wrapper’. The term
‘gathered’ is defined in the patent, in the
context of a tobacco sheet, as denoting that the sheet ‘is
convoluted, folded or otherwise compressed or constricted
substantially transversely to the cylindrical axis of the
rod’.

The Patent was opposed by Yunnan Tobacco International Co., Ltd,
who submitted that such a definition would include a gathered sheet
which had been disclosed in the prior art, and that the patent
should be rejected as the invention was unpatentable. The
Opposition Division took a different view, however, citing little
more than a Wikipedia entry for the term ‘gather’ in the
context of sewing, in which it is more widely used. The Opposition
Division used the interpretation for ‘gathered’ as
‘geometrically modified into a more complex shape’, derived
from the Wikipedia entry, as an analogy of how the patent should be
interpreted, in the absence of a more established interpretation.
The complexity of the geometric modification was interpreted to
exclude, for example, the simpler rolling of a sheet (as was
disclosed in the prior art), and as such, the claims were
considered to be patentable and the opposition was rejected.

The rejection of the opposition was appealed. In its
consideration, the Technical Board of Appeal identified diverging
lines of case law as to when the description should be taken into
account when interpreting an allegedly clear term, and referred the
following questions to the EBA:

(1): Is Article 69(1), second sentence, EPC and Article 1 of the
Protocol on the Interpretation of Article 69 EPC to be applied to
the interpretation of patent claims when assessing the
patentability of an invention under Articles 52 to 57
EPC?

(2): May the description and figures be consulted when
interpreting the claims to assess patentability and, if so, may
this be done generally or only if the person skilled in the art
finds a claim to be unclear or ambiguous when read in
isolation?

G 1/24 Answer: Yes, always

(3): May a definition or similar information on a term used in
the claims which is explicitly given in the description be
disregarded when interpreting the claims to assess patentability
and, if so, under what conditions?

G 1/24 Answer: Dealt with in answer to question (2).

The Protocol on the Interpretation of Article 69 EPC is an
integral part of the Convention and was introduced by agreement of
the member states in 2000 to help further harmonise patent law and
to promote innovation and economic growth in Europe. The wording of
the Protocol referenced in question (1) provides the possibility of
interpreting the scope of protection of a European patent by
reference to the description and drawings in a way which combines a
fair protection for the patent proprietor with a reasonable degree
of legal certainty for third parties. The Protocol states that the
protection should not be defined by strict, literal meaning of the
wording used in the claims, nor that the claims provide only a
guideline. However, the Protocol has been generally interpreted by
the EPO as applying to determination of claim scope in infringement
actions before national courts and the UPC, rather than in
assessing patentability of claims during prosecution (whether this
approach is justified is perhaps the subject of a separate
debate).

The EBA considered that Article 84 EPC, requiring that the
claims define the matter for which protection is sought, is the
only credible alternative as a legal basis for claim interpretation
to assess patentability, but that this provides only an instruction
as to the formal requirement of the content of a claim, rather than
guidance on its interpretation.

Despite the resulting absence of clear legal basis for claim
interpretation in the EPC, the EBA does note that consistent
principles can be derived from the case law.

Firstly, it is established that the claims provide the starting
point. Secondly, divergence in case law as to whether the
description and drawings should always be considered, or only in
the event of ambiguity or a lack of clarity, should be resolved in
a way which avoids divergence from the practice of national courts
and the UPC, and which avoids conflict with the Protocol, by
rejecting the interpretation that the description and drawings
should only be considered in the event of ambiguity. Further, the
EBA notes that the consideration that the finding that a claim is
clear and unambiguous is an act of interpretation, not a
preliminary stage to such interpretation, such that the
identification of a reason to justify consideration of the
description and drawings is not logical.

Conclusion

As a consequence, the importance of the content of the
description and drawings of a patent specification is confirmed.
Definitions of terminology must be carefully considered,
particularly in cases where such definitions diverge from those
which are more widely established. If a term in a claim has a clear
meaning, a broader definition in the description may cause a claim
to lack patentability. As an aside, the interpretation of the
Opposition Division in this case of the term ‘gathered’
from the field of sewing is an interesting exercise in how a widely
established meaning of a term might be derived.

The relationship between the description and drawings and the
claim language must also, as is being considered via a growing body
of EPO case law, be considered to ensure that there is no conflict
resulting from amendment of the claims during prosecution, in which
description wording might, for example, affect the patentability of
a claim via its effect on the interpretation of the claim wording.
Further, such a conflict in meaning may have implications when
testing if an amendment is supported by the application as filed
(Article 123(2) EPC) or if the claim scope has been broadened after
grant in opposition proceedings (Article 123(3) EPC). There may,
therefore, be an increased focus on clarity of terminology during
prosecution as a result of this decision.

While there are consequently practical points to note in terms
of how patent specifications should be drafted, the overriding
alignment of this EBA’s decision with the harmonisation
philosophy underlying the EPC is exceptionally positive, and the
simplicity and logic of the EBA’s decision is to be
commended.

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