In patent invalidation, administrative confirmation of patent rights, and patent infringement litigation, “common knowledge” often becomes the decisive factor in assessing a patent’s inventiveness. A key practical question is: which types of documents can qualify as evidence of common knowledge? Must they be textbooks, or can reference books and industry manuals also count? Recent decisions from China’s Supreme People’s Court provide nuanced guidance: the determination depends on the substance and characteristics of the documents, not merely their format.

Legal Basis and Representative Cases

The Patent Examination Guidelines explicitly list three typical sources of common knowledge evidence: technical dictionaries, technical manuals, and textbooks. For instance, in a notable administrative review case involving a biomedical research institute in Jiangsu [SPC case No. 2023-13-3-024-037], the Supreme Court clarified that evidence outside these three categories can be recognized as common knowledge depending on the document’s format, content, audience, and dissemination scope.

In this case, a specialized research book on oncology was rejected as evidence. The Court noted that the book presented cutting-edge developments for researchers rather than basic technical knowledge and was intended as a reference rather than a standard textbook.

When Reference Books Can Count?

However, another Supreme Court case (2024 SPC case No. 1244) illustrates that reference books may qualify. Several technical reference works on chemical fertilizers and granulation towers, published before the patent’s filing date, were accepted as evidence of common knowledge. The Court emphasized that these books systematically presented mature, foundational technical knowledge in their fields. Even if labeled “reference books,” they were sufficiently authoritative and widely accessible to serve as evidence of common technical understanding.

Practical Implications

Broaden the search beyond textbooks. Technical manuals, industry references, and engineering guides may be accepted if they document established, mature, and widely recognized knowledge. Agents should focus on content relevance rather than labels on the cover.

Countering challenges to reference books. When opposing counsel argues that a reference book is not a legally recognized source, practitioners should present objective evidence: content summaries showing foundational knowledge, reprint frequency, publisher authority, circulation, and citations in industry or academia.

Support with multiple sources. No single reference is conclusive. Supplementing a core reference with additional patents, textbooks, or technical publications strengthens the argument that the knowledge is indeed common in the field.

Conclusion

The recognition of common knowledge evidence is not a binary exercise. Understanding the Supreme Court’s reasoning, confidently considering diverse sources during evidence collection, and emphasizing substantive content during litigation are key strategies for navigating complex intellectual property disputes in China.