Introduction

The object of a patentability search is “prior art.” A clear prior art definition may appear straightforward, yet its precise delineation involves many nuances worth exploring in depth. What counts as “disclosed”? Which point in time serves as the dividing line? Does content on the Internet count? How should Use Disclosure and Oral Disclosure be assessed? Accurately grasping these boundaries directly affects the comprehensiveness of a patentability search and the correctness of its conclusions.

This article systematically sorts out the prior art definition, scope, and key boundary issues of “prior art” in the sense of patent law, helping you build a complete cognitive framework for prior art in patentability searches.

Legal Prior Art Definition

EPC Definition of Prior Art

Pursuant to EPC Art. 54, the State of the Art (Prior Art) comprises everything made available to the public by means of a written or oral description, by use, or in any other way, before the date of filing of the European patent application (or before the priority date).

This definition comprises three key elements:

Element One: “Before the Date of Filing” — The Temporal Boundary

The filing date (or the priority date) serves as the dividing point. Technology disclosed on the filing date itself does not constitute prior art. If a priority right is claimed (pursuant to the Paris Convention), the priority date is used as the benchmark for assessment.

This is an absolute temporal dividing line. Any disclosure occurring after the filing date cannot constitute “prior art” that may be used to assess the novelty or inventive step of that application.

Element Two: “In Any Way, Anywhere” — The Geographic and Formal Scope

Like the major jurisdictions worldwide, the EPC adopts the absolute novelty standard (the “worldwide novelty standard”). Technology disclosed in any manner at any location in the world constitutes prior art. This differs from the “relative novelty” standard (limited to domestic disclosure) that some countries historically adopted.

Element Three: “Made Available to the Public” — The State of Disclosure

“Made available to the public” is not equivalent to “how many people actually know about it.” The core concept here is that the information is in a state such that the public could become aware of it if they wished to. Even if no one actually took the initiative to access it, as long as it is objectively in a state accessible to the public, disclosure is established. In EPO case law, “made available to the public” means that the information was accessed in a lawful manner by at least one person who is not bound by a duty of confidentiality.

Three Modes of Disclosure of Prior Art

1. Publication Disclosure

Publication Disclosure is the most important source of prior art, including:

• Patent documents: patent application documents and granted patent documents published by patent offices of various countries (this is the main body of patentability search work)
• Scientific and technical journals and academic papers: including both print and electronic journals
• Books and textbooks: formally published technical books
• Conference papers and presentations: papers and presentation materials from academic conferences and technical forums
• Theses and dissertations: master’s and doctoral theses (theses made publicly available through platforms such as ProQuest, CNKI, etc. constitute Publication Disclosure)
• Technical standards and specifications: national standards, industry standards, international standards
• Product manuals and user guides: technical documentation publicly distributed with products

Key criterion: whether the information is in a state accessible to the public. An internal report circulated only within a company does not constitute Publication Disclosure; once uploaded to a public website or distributed to unspecified persons, it constitutes Publication Disclosure.

2. Use Disclosure / Disclosure by Use

Use Disclosure refers to making a technical solution available in a state such that the public can learn its essential content through acts such as manufacturing, use, sale, import, exhibition, or demonstration.

Important Boundaries:

• Selling a product does not automatically equal Use Disclosure — if the product itself cannot reveal its internal technical details through reverse engineering (e.g., a confidential formulation), it does not constitute Use Disclosure. However, if the product structure can be understood through disassembly and analysis, selling that product constitutes Use Disclosure.
• In jurisdictions adopting the absolute novelty standard (such as the EPC, China, Japan, etc.), Use Disclosure, like Publication Disclosure, can constitute prior art if it occurs anywhere in the world. For example, a public sale, use, or exhibition act abroad may equally destroy the novelty of a patent application filed in Europe.

3. Disclosure by Other Means

Includes Oral Disclosure (speeches, lectures, broadcasts, television), Internet Disclosure, etc.

Special Characteristics of Internet Disclosure:

• Web page content, social media posts, GitHub code repositories, product crowdfunding pages, etc. may all constitute prior art
• Key assessment elements: Can the time of disclosure be determined? Can the content be proven?
• In patentability searches, content discovered through search engines, GitHub, industry forums, and similar channels is worth including in the analysis (note: retain screenshots/archives to preserve evidence of the publication date)

Special Case: Conflicting Application

Pursuant to EPC Art. 54(3), a Conflicting Application is treated as part of the prior art for assessing the novelty of a later application (note: it cannot be used to assess inventive step).

What Is a Conflicting Application?

A Conflicting Application is a patent application document that was filed before the filing date of the application under examination but published or laid open only after that filing date, which contains the same invention or utility model as the later application.

In plain terms: A filed a patent application in January 2023, and that application was published in July 2023. B filed a patent application with identical content in March 2023. For B’s application:

• A’s application was filed in January 2023 (earlier than B’s March filing)
• But as of March 2023 (B’s filing date), A’s application had not yet been published
• Therefore A’s application is not “prior art” with respect to B’s application (because it was not yet available to the public in March)
• However, A’s application constitutes a “Conflicting Application” against B’s, and may be used to assess B’s novelty

Significance of Conflicting Applications in Patentability Searches

In a patentability search, you need to pay special attention to conflicting applications and documents published around the filing date. A patent application filed before your filing date but published only after it can also destroy novelty.

Filing Date / Priority Date: Determining the Time Benchmark

What Is a Priority Right?

The Paris Convention establishes the priority system: after filing a first application in one country, an applicant who files an application for the same invention in other countries within 12 months (for inventions and utility models) or 6 months (for designs) may claim the date of the first application as the “priority date.”

For an application claiming priority, the priority date, rather than the actual filing date, is used as the benchmark when assessing novelty and inventive step.

How to Apply This in Patentability Searches

• For a PCT application claiming priority, the patentability search should use the priority date as the temporal dividing point
• For an ordinary domestic application without a priority claim, use the filing date as the dividing point
• During the search, the following must be confirmed: (1) whether the application claims priority; (2) whether the priority claim is valid (in some circumstances, newly added content cannot enjoy priority)

Prior Art Definition and Search Scope

Based on the above definitions, the search scope for a patentability search should be:

Must-Cover

Optional Supplements

Judgment of Key Boundary Issues

Q1: Does technology used internally within a company count as prior art?

If it is limited to internal company use, subject to a duty of confidentiality, and not disclosed to the outside world — it does not constitute prior art. However, if the company presents the technical solution to clients or partners without being bound by a confidentiality agreement — it may constitute prior art.

Q2: Does code placed in a private GitHub repository count?

A private repository is not open to the public — it does not constitute prior art. However, once the repository is set to public, it constitutes Publication Disclosure.

Q3: Does a WeChat Moments post published by the inventor before the filing date count as prior art?

If the Moments post is set to public visibility (not visible only to oneself / only to selected friends), and the technical content can be seen by unspecified persons — it may constitute prior art. This is the risk of the inventor’s own “premature disclosure.” It is recommended not to disclose a technical solution in any public manner before filing a patent application.

Q4: Does a product introduction on a crowdfunding platform count?

Public product pages on crowdfunding platforms such as Kickstarter and Indiegogo generally constitute Publication Disclosure. If the page describes the technical solution of the product and the time of disclosure predates the filing date — it constitutes prior art.

Key Takeaways: Prior art refers to technology made available to the public anywhere in the world before the filing date (or the priority date). This prior art definition includes Publication Disclosure, Use Disclosure / Disclosure by Use, and disclosure by other means. Teams can use PatSnap Analytics to support global prior art review across patent data sources. A Conflicting Application, though not prior art per se, may be used to assess novelty (but not inventive step). A patentability search must cover global patent documents + major non-patent literature sources, and correctly apply the temporal benchmark of the filing date / priority date.