Grounds of unpatentability in an inter partes review (IPR) are “only on the basis of prior art consisting of patents or printed publications”1 according to a determination made by the Patent Trial and Appeal Board (PTAB) involving inquiry into the facts and circumstances surrounding the reference’s disclosure to the public.2  Public accessibility is the touchstone, which can be established by demonstrating that persons interested and ordinarily skilled in the subject matter can reasonably locate it.3  In some cases, qualification of the prior art as a printed publication is pivotal to the outcome of the IPR proceeding.

Failure to make a threshold showing that the submitted document qualifies as a printed publication can result in denial of the petition.4  Even when a threshold showing of qualification is found at the institution stage, the PTAB can still reject the document as a printed publication in a final written decision.  For example, in BLD Services, LLC v. LMK Technologies, LLC, although Petitioner made a threshold showing that two documents qualified as printed publications, Petitioner did not supplement the record to support the prior art status of those documents, and the PTAB concluded those documents did not qualify as printed publication.5  And in TRW Automotive U.S. LLC v. Magna Electronics Inc., the PTAB found in its final written decision that Petitioner’s ground of unpatentability necessarily fails when it relied on a document which was excluded, noting that Petitioner did not serve any supplemental evidence in response to patent owner’s objections to the reference.6 

The burden to prove public availability before the critical date falls on the petitioner. 

“The party seeking to introduce the reference should produce sufficient proof of its dissemination or that it has otherwise been available and accessible to persons concerned with the art to which the document relates and thus most likely to avail themselves of its contents.”7 

Relying on admission of another party, such as patent applicant, may not be sufficient to prove printed publication.  For example, in L-3 Communication Holdings, although applicant called the document a printed publication when responding to an office action, that action did not establish the report as a printed publication.8 

One way to meet the burden of proving public availability is by declaration or testimony.  In ZTE Corporation, an expert testified to the availability of a standard as of dates listed on the top of a printed specification and opined that a person of ordinary skill in the art working in the relevant industry would certainly be aware of the publication and availability.9  Crediting that testimony, the PTAB determined that Petitioner has made a threshold showing establishing that the standards are a prior art printed publication.10  In L-3 Communications Holdings, a declaration from a director of the company that the manual was distributed to customers at least 201 times in two years and the company did not restrict its customers’ use or dissemination showed sufficiently that it was a prior art printed publication.11  In Motorola Mobility LLC, the PTAB determined the white paper to be prior art when a vice chair of a working group declared that all submissions were publicly available.12 

Declarations of this nature should include specific details about public accessibility and critical date of the reference.  In Kinetic Technologies, Inc. v. Skyworks Solutions, Inc., a declaration from a twenty-two year employee of the company did not establish that the product data sheet was made public.13  The PTAB reasoned that the statement such documents were made publicly available shortly after the footer dates needs further explanation.14 


Whether a document is a printed publication involves factual analysis on a case-by-case basis, and patent owners and petitioners should keep in mind the following when dealing with them:

  • When facing a petition that uses a printed publication as prior art, patent owners might avoid or limit institution by showing that a petitioner has failed to provide sufficient evidence that the prior art satisfied the printed publication standard. 
  • Equally, petitioners should do what they can to meet their burden of proof in their original petition and continue to provide relevant evidence through trial, including submitting supplemental evidence or supplemental information, such as declarations from individuals who have knowledge about public accessibility and critical date of the document.