Welcome to the new version of the Patents Manual. Please note there are changes to the numbering and sequence of the chapters and pages in the manual. You are encouraged to take the time to explore and familiarise yourself with this new structure. Non-Patent Literature

Date Published

Key Legislation:

PCT ISPE Guidelines:

  • para 11.18 Disclosure Made on Web Sites of Unknown Reliability

Related Chapters:

Key Topics on this Page

  • Establishing Publication Dates:
    • Where the publication date can be established
    • Where the publication date can be established with a supporting document
    • Where the publication date cannot be established

In some technologies (such as biotechnology or electronic commerce) a search of non-patent literature (NPL) is known to be more valuable than patent searches. In such cases it is appropriate to conduct NPL searches in conjunction with patent searches. NPL can generally be considered to relate to any form of literature that lies outside of patents. Relevant NPL is usually found in the form of journal articles, news articles, books, and websites.

The same security considerations apply for NPL searching as for patent searching. Some NPL databases are available both over the Internet and via dedicated connections such as STN and EPOQUE. All search considerations being equal, it is preferable that searches be performed via dedicated connections for reasons of added security. It is essential that searches, involving the use of search terms that might disclose the invention, be conducted via dedicated connections.

Different technology sections tend to utilise different NPL databases and websites. Subject matter experts should be consulted if there is any doubt as to where to conduct a NPL search. This is particularly important when considering searches covering multiple technological areas.

Note that in many technologies, the expectation is that a search of patent literature will suffice. If no citable art is found in the patent literature but examiners believe citable material should exist in the NPL, then it may be appropriate to consider a NPL search on the Internet. However, in such cases NPL searches on the Internet should not be a routine activity.

An important determinant in selecting NPL search areas is the ability to establish publication of material found on electronic journal sites, databases, and independent web sites. If equivalent paper versions are found to exist, then there is no issue regarding establishment of publication and such material can be readily cited.

Sources of NPL found solely on the Internet fall into two categories. The first is that of ‘Trusted Publishers’ such as respected electronic journals, newspapers, periodicals, television, and radio stations etc. Many scientific, electrical, and medical journals are now published only electronically. Since existing material in these databases remains static, the publication dates associated with such material can be accepted at face value as we do for patent specifications.

The second category is of ‘Unknown Reliability’ such as belonging to private individuals, private organizations, commercial websites etc. The material found on such sites can be very fluid, being subjected to continual change in content or even removal altogether with little indication of what content was available at any point in time. In these circumstances where it is difficult to uphold arguments of publication of appropriate material, the Internet Archive Wayback Machine (http://www.archive.org/) may be able to establish a prima facie publication date for the web page, or to find out what the particular web site looked like and what information it disclosed at a particular date in the past.

In the light of publication difficulties with web sites of ‘Unknown Reliability’, it is far more preferable to search and rely on material from ‘Trusted Publishers’.

Establishing publication dates

Websites of organisations whose business it is to publish documents (for example, Journals, Newspapers, Universities, and YouTube) are generally not considered to be of “unknown reliability”. Consequently, the publication dates indicated therein for their content can be accepted as accurate.  

Websites and/or pages whose purpose is not publication (e.g. social media sites, private or corporate websites) may be considered to be of “unknown reliability” and the publication dates indicated therein, where present, may not be accurate. In such cases, supporting evidence and/or a Wayback Machine capture is likely to be required.

In all cases, examiners are required to use their judgement in order to determine whether supporting “L” documents and/or the Wayback Machine are required to establish the publication date of an electronic citation.

Where the publication date can be established

When citing an electronic document from a website of questionable reliability, or when seeking additional verification of an indicated publication date, the examiner should use the Internet Archive Wayback Machine to establish a prima facie publication date for a version of the webpage that predates the priority date of the invention.

The examiner should print (to PDF) the relevant disclosure from the Wayback Machine. The printed disclosure includes the URL of the webpage at the bottom along with its publication date. (Note that the first eight numbers appearing in the URL of the webpage represent the date of publication of the document).


  • As a document from the Internet Archive Wayback Machine provides both the disclosure and a publication date of that disclosure, it is not necessary to cite the webpage originally identified. The disclosure from the Internet Archive Wayback Machine can be cited as an "X", "Y", or "A" citation, as appropriate.
  • Where the examiner has identified a relevant document from a website of questionable reliability but:
    • is unable to find a suitable Wayback Machine capture; and
    • the nature of the disclosure is such that the examiner considers that the date indicated.

thereon establishes a prime facie publication date,

The document may be cited with an "X", "Y", or "A" indication, as appropriate, notwithstanding the character of the website / web page from which is has been sourced.

See Annex L for further information on capturing internet disclosures using the Wayback Machine.

Note that in Voxson Pty Ltd v Telstra Corporation Limited (No 10) (2018) FCA 376, Perram J found that pages obtained from the Wayback Machine were hearsay evidence. This does not affect the ability of examiners to use the Wayback Machine, but attorneys may use this argument in an attempt to discredit the Wayback Machine. A full discussion of hearsay evidence is found in 7.5.2 Admissibility of Evidence. If in any doubt about how to respond to such an argument, examiners should consult their supervising examiner and/or Oppositions.

Where the publication date can be established with a supporting document

Where a first document is identified which is relevant to the claim(s) but does not have a publication date AND a second document is located which prima facie identifies the publication date of the first document, the first document should be cited with the appropriate indication of relevancy (“X”, “Y”, etc) and the second document as an “L” document. The description of the “L” document should indicate that it provides evidence of the publication date of the first.

An example where such a situation may arise is where an abstract is identified, describing the citable technical content relevant to a claim but lacking a publication date. In support of this citable document is a program of a conference indicating that a presentation was made on a specific date having the same title as that of the identified abstract, and therefore, prima facie indicating the date of public disclosure of the content of the abstract.  

In this instance, the abstract should be cited with the relevant “X” or “Y” categorisation, and the conference program, which establishes the publication date of the abstract, is categorised as an “L” document.

Where the publication date cannot be established

In the case where the examiner is unable to establish the date of publication of an internet disclosure but wishes to cite the publication (for example, because the document would otherwise be relevant to the inventive step and/or novelty of the claimed invention), the document may be cited as “L” category without an "X", "Y", or "A" indication. Such a document may not be relied upon for the purposes of novelty and/or inventive step.

When citing such documents in an ISR/ISO, the ISR should include a brief reason for citing this document (See Citation Examples). However no discussion of “L” only document is required in the ISO.

The application of symbol "L" for Internet citations is documented in paragraph 11.18 of the PCT International Search and Preliminary Examination Guidelines PCT/GL/ISPE/12.

Amended Reasons

Amended Reason Date Amended
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