June 2026 Following G 1/24, which held that the description must always be consulted when interpreting claims for patentability, a new referral to the Enlarged Board of Appeal – G 1/26 – asks whether that same approach applies more broadly, including to added matter, and whether the description can go beyond merely explaining claim terms to actually influence their meaning. The referral raises a preliminary admissibility question and then poses a series of substantive questions that go to the heart of how claims are interpreted across different areas of the European Patent Convention (EPC).
Admissibility: Should the Enlarged Board Answer at All?
The first question in G 1/26 is procedural. The referring Board asks whether a referral is “required” under Article 112(1) EPC where the legal issue arises in the pending case but the Board has not yet resolved all other appeal issues.
This reflects a concern that the question was referred prematurely, i.e., before the case was otherwise ready for decision. If the Enlarged Board considers this fatal, the referral could be refused without the substantive questions ever being answered.
The General Law of Claim Interpretation
Question 2 is the heart of the referral and addresses the issue left open by G 1/24.
Question 2(a) effectively asks: if claims are the starting point and basis for assessing patentability, does that prevent a feature disclosed only in the description from being read into the claim, especially where doing so would narrow it?
Two competing approaches frame the debate:
Approach A = Claims have primacy. The claim defines the invention. The description cannot add limitations. This approach means the description is very much secondary in claim interpretation.
Approach B = Claims and description form a single interpretative exercise. This approach means the skilled person reads the patent as a whole, and the description may establish the meaning of claim terminology.
Question 2(b) follows if the answer to 2(a) is “no.” It effectively asks whether claim interpretation is a unitary process of reading the claims together with the description, subject to a limit: the description can inform interpretation, but it cannot impose an interpretation that contradicts the skilled person’s general technical understanding.
This is arguably the most important question in the referral, because it asks where the boundary lies.
Added Matter
Question 3 turns to Article 123(2) EPC specifically.
Question 3(a) effectively asks whether, when assessing added matter, each technically sensible interpretation of a claim term (based only on the claim wording) must be tested against the original disclosure.
The referral gives a concrete example: a claim to a “ratio of titanium to nitrogen” could mean a weight ratio, an atomic ratio or another technically meaningful ratio. Must all of these possibilities be considered?
Question 3(b) effectively asks the converse: is it enough to consider only interpretations obtained after reading the whole patent specification?
In other words, can the description narrow the field of possible meanings before the Article 123(2) EPC analysis is carried out?
The Bigger Picture
G 1/26 asks a deceptively simple question: does the EPO interpret claims on a “claim-first, description-assisted” basis, or do the claims and description form a single, unified interpretative exercise?
It then goes on to ask whether the answer changes depending on the legal context, i.e., whether the question is one of novelty and inventive step, added matter or potentially other requirements of the EPC?
Should the EBA choose to admit the referral, the answers to these questions will shape patent prosecution and litigation strategy at the EPO for years to come.
