EPO Board Rules on Claim Ambiguity; Belgian Patent Litigation Reviewed
A recent Board of Appeal decision clarifies claim interpretation, while a review highlights key developments in Belgian patent enforcement.
By Giovanni Sapere
2 min readHuman-Edited, AI-Assisted
The European Patent Office (EPO) Board of Appeal recently addressed the issue of claim ambiguity in a case concerning an e-cigarette cartridge, impacting how "added subject-matter" is assessed. Concurrently, a review by the Stibbe IP team summarized significant Belgian patent litigation decisions from mid-2025 to mid-2026, covering topics like injunction liability and cross-border seizure orders.
EPO Board Clarifies Claim Ambiguity
The European Patent Office (EPO) Board of Appeal, in case T 0977/25, ruled on the ambiguity of the word "it" within an amended method claim for an e-cigarette cartridge The IPKat. The Board found that an "unresolved ambiguity" in the claims could lead to the addition of subject-matter, as both possible interpretations were considered The IPKat. This decision offers insights into the risks of inconsistencies and description amendments, particularly in light of the G1/24 and G1/25 duo of decisions, which relate to clarity and amendments The IPKat.
“an “unresolved ambiguity” in the claims added subject-matter by virtue of the fact that both possible interpretations”
— Board of Appeal in T 0977/25
Belgian Patent Litigation Developments
The Stibbe IP team published its annual review of significant Belgian patent litigation decisions, covering the period from mid-2025 to mid-2026 The IPKat. The review detailed developments concerning injunction liability, which refers to a party's responsibility for damages incurred due to an injunction, and cross-border saisie orders The IPKat. Saisie orders are seizure orders, often used to gather evidence in intellectual property disputes across national borders The IPKat.
Implications for Patent Practice
The EPO Board's decision in T 0977/25 underscores the importance of precise language in patent claims to avoid ambiguity, which can lead to issues of added subject-matter during examination or opposition proceedings The IPKat. For patentees and applicants, careful drafting and amendment strategies are crucial to ensure clarity and avoid potential challenges based on inconsistent interpretations The IPKat. The Belgian litigation review highlights ongoing legal trends in patent enforcement within Europe, particularly regarding the practicalities of seeking remedies like injunctions and evidence collection across borders The IPKat.
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