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IP Blog / Defensive publication or patent application: Which works best?

Defensive publication or patent application: Which works best?

There are many forms of Intellectual Property (IP) defense, some of which can appear unconventional or counterintuitive at first glance. The action typically called a "defensive publication" falls into this category, but it has a specific, valuable purpose in your IP arsenal. 

Opting for a defensive publication instead of a patent application can be the best move in some situations. But you must exercise a certain degree of caution when you use this IP defense — and that level of discretion begins with understanding the ins and outs of the strategy.

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What is a defensive publication?

Any public announcement that contains the essential details or workings of an IP asset — typically a patent-eligible invention, method or system — can constitute a defensive publication.

Also sometimes known as a defensive disclosure, this publication generally includes an abstract, drawings, photographs, claims, description and any other elements you would have in a patent application for a given jurisdiction. Like its better-known patent counterpart, a defensive publication illustrates enablement and validates that the disclosed technology is novel, useful and non-obvious (or "contains an inventive step" in a European legal context).

The ideal effect of a defensive publication is to deter rival organizations and / or inventors by establishing that the depicted invention is prior art. Consequently, someone filing a patent application for an identical or very similar invention would most likely be rejected by examiners because the defensive disclosure would show up in a thorough prior art and patent search.

In practice, there is no official procedure for releasing a defensive publication, and any publicly accessible medium could suffice; it could be a self-printed booklet, a website blog post or a paid advertisement in a major media outlet. But keep in mind that "public" is the crux of the matter here. For this disclosure to have substantive weight — especially if it is likely to provoke legal challenges — it would be wise to release it to the relevant audience through a technical or industry journal, an academic publication or a prior-art publishing service.


Though a newspaper could satisfy the needs of disclosure, the resulting defensive publication might not withstand committed opposition. A specialist journal or magazine with adequate distribution would be a more suitable choice.

When is a defensive publication more useful than a patent application?

Defensive publication may be a better option than seeking patent protection in a number of cases. The following are among the most common circumstances where this might be:

  • Likelihood of high costs: The expenses necessary to file, attain and maintain a patent grant can be significant, especially when it comes to keeping up with regular patent renewal payments in multiple jurisdictions. If these costs noticeably outweigh the benefits of full-fledged patent protection, disclosure can be a suitable alternative.
  • Fast-moving industries: Rapidly developing technology sectors — especially consumer electronics — are full of products that become actually or effectively obsolete within just a few years. While some elements in this field, like battery or chip technology, may have extended shelf lives that would benefit from patent rights, there are numerous other instances in which patenting would be cost-inefficient.
  • Fierce competition: If you know your competitors are working on an invention identical or very similar to yours, the technical disclosure of your IP could throw a big part of their strategy into disarray. In this example, the best defense is indeed a good offense.

In all of these cases, a defensive publication puts the IP into the public sphere. Even disclosing only certain aspects of the invention ensures that the subject matter becomes prior art, making it extremely difficult for a patent examiner to allow any meaningful claims that contain the published material. Thus, a defensive publication can secure your freedom to operate while reducing filing, prosecution and maintenance expenses.

Defensive publication drawbacks

Sometimes, taking the defensive publication route is not the right move — or can even backfire. In the end, defensive publishing authorizes anyone to take your IP and use it as they please.


A defensive publication is a double-edged sword and can affect you as much as your competition. By disclosing, you allow anyone to exploit your invention and forfeit exclusivity rights that could be used to generate licensing revenue.

Also, because defensive publication is equivalent to prior art and bars the relevant material from being the subject of any meaningful patent protection, it counts against all future filings. This means your own filings are impacted in the same way as your competitors'. There are some narrow exceptions to this that vary around the world, for example:

  • Utility or design patent filings in the United States with filing dates no later than one year after the disclosure can contain an inventor's prior art. Otherwise, Title 35 Section 102(a)(1) provisions apply.
  • Japanese Patent Law (JPL) Article 30(2) provides a similar one-year grace period after the defensive publication, during which a patent application containing prior art can still be filed.
  • Under Article 55 of the European Patent Convention (EPC), the European Patent Office (EPO) will not count public disclosure against a patent applicant provided they file no later than six months after disclosure and the prior art was publicized through some malfeasance ("evident abuse") or as part of "an official, or officially recognized, international exhibition." (These are primarily scientific and industry exhibitions.)

Last but not least, any lack of clarity in a defensive publication (e.g., informal or vague language that could be potentially misinterpreted or misunderstood) weakens its efficacy. Precision is key, and the disclosure must also avoid excessively detailed information as this could similarly inhibit clearness.

Crafting a multifaceted IP strategy

No sound IP management / protection strategy is myopic or inflexible — it must be ready to use all available tools at the appropriate times. Identifying when to publish defensively and when to go down the traditional patent route is critical to your long-term innovation goals.

The decision to employ a defensive publication program or similar disclosure method should not be taken lightly and must consider various aspects. These include, but are not limited to, market value, the state of the industry, the potential to create (or reduce) competitive advantage and how filing — or disclosure — would affect your other and future IP.

Published technical disclosures, used in conjunction with patents, can strengthen an IP portfolio and facilitate market expansion by preempting the competition. Consult Dennemeyer's patent law experts to discuss the specifics of these tactics and how (and when) it is best to implement them in your business plan.

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