In its judgment of July 28, 2026 (X ZR 98/24 – “Überbrücktes Netzwerk”), the BGH confirmed that general statements of optionality in a patent application are not a wildcard for later claim amendments.

Here are the core points of this key ruling and how it impacts patent drafting:

The Case Background

• The Patent: EP 2 057 796 (relating to point-to-multipoint functionality in a bridged Layer-2 Ethernet network) describes a method performed by a switch to prevent direct communication between customer devices (CPEs) by marking and discarding specific unicast frames.
• The Conflict: The Federal Patent Court (BPatG) had declared the patent null and void. The patent proprietor defended the patent in amended versions. The claims mandatorily required discarding certain unicast frames while forwarding all other frames.
• The Defense: The proprietor argued that this combination was originally disclosed because the description indicated that the steps in the illustrated embodiments were optional or “not mandatory”.

The Core Legal Ruling

The BGH dismissed the appeal and confirmed the patent’s nullity. The Court ruled that:

• A general hint in the original application stating that individual steps of an embodiment do not necessarily have to be implemented is not sufficient to directly and unambiguously disclose a modified method where those steps are replaced by a specific, concrete alternative procedure.
• Because the specific procedure claimed—discarding only unicast frames and forwarding all others—was not directly and unambiguously described in the original filing, the amendment constituted inadmissible added matter (unzulässige Erweiterung).

Key Takeaways & Best Practices 

How can you protect your applications from similar nullity traps under German and European practice?

• Ditch Generic “Optionality” Boilerplates: Simply stating that “individual steps of the embodiment do not necessarily have to be implemented” will not justify a later selection of a modified procedure. General disclaimers are not a substitute for concrete disclosure.
• Explicitly Disclose Specific Alternatives: If a step is optional or replaceable, you must explicitly describe the concrete alternative steps and how they combine with the remaining features.
• Draft Multiple Independent Scenarios: Instead of relying on a single detailed embodiment with “optional” disclaimers, draft the description to show distinct, fully functional alternative scenarios and sub-combinations of features .
• Expect Strict Enforcement: The BGH continues to strictly apply the “gold standard” of direct and unambiguous disclosure, fully aligned with the EPO.