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. Prior Use, Secret Use, and Confidential Information

Date Published

Key Legislation:

Patents Act:

  • s7(1) Novelty
  • s9 Secret use  
  • s18(1)(b)(i) Patentable inventions
  • s24 Validity not affected by making information available in certain circumstance
  • s27 Notice of matters affecting validity of standard patents 
  • s102 What amendments are not allowable?
  • s104 Amendments by applicants and patentees  
  • Schedule 1 Dictionary

Patent Regulations:

  • reg 2.2 Information made publicly available--recognised exhibitions
  • reg 2.2A Information made publicly available--learned societies
  • reg 2.2B Information made publicly available--reasonable trial of invention
  • reg 2.2C Information made publicly available--other circumstances
  • reg 2.2D Information made publicly available without consent--period


This section discusses the prior use of an invention, or the doing of an act, as a type of relevant prior art information, and the requirements of that use or act in order for it to be novelty destroying. Photographs may sometimes be used as evidence of prior use.

Secret use refers to commercial use of the alleged invention. It is a separate ground of invalidity, distinct from novelty, that is intended to stop a patentee gaining an effective extension of term. This section discusses what is defined as prohibited secret use.

Particular prior art information that was supposed to be confidential information may possibly be disregarded for the purposes of novelty and inventive step. This section discusses the requirements of such confidential information.

Prior Use

Prior art information that is made publicly available through doing an act, before the priority date, anywhere in the world, can be considered for novelty purposes. Doing an act is otherwise known as prior use. An example of prior use includes displaying or advertising a product for sale.

The requirements for a prior use or act to be novelty destroying are that:

  • The act must have been accessible to at least one member of the public in circumstances where that person would be free in law and equity to make use of the information obtained from it as that person saw fit;

  • The act must have resulted in disclosure of all the essential integers of the claim so that a person skilled in the art would be able to carry out the invention without the need to gather further information or further invention, or in other words, an enabling disclosure;

  • The skilled person must, on inspection of the act, be able to comprehend the complete invention. Mere observation of the product may not be an enabling disclosure if each of the features of the invention (for example, internal workings of the product) are not on display or publicly available;

  • It is not possible to combine an act and a document; and

  • The onus lies on the party seeking to rely on the disclosure (that is, the examiner if the prior use is raised for novelty purposes during examination).

Photographs as a Disclosure

Examiners may be required to consider a photograph as an alleged anticipation, most likely as evidence of prior use. The existence of the photograph would likely be raised in a notice under s27.

Where photographs are used as evidence of prior use, they have the potential to be used as novelty citations with the date the photograph was taken as being the relevant date. However, the requirements as listed above for a prior use or act to be novelty destroying apply. The requirement most relevant to photographs is enablement; does the photograph show all the essential features of the invention?

It may be the case that a photograph appears to be a suitable novelty citation and is raised during examination but will be difficult to maintain in light of applicant arguments. Nevertheless, raising the photograph as a citation initially is important from a customer-centric viewpoint.

The use of photographs for novelty purposes during re-examination and opposition hearings could be more nuanced because additional evidence can be submitted and considered.

Relevant Case Law

Damorgold Pty Ltd v JAI Products Pty Ltd (2015) FCAFC 31 elaborates on the requirements for a prior use to be novelty destroying.

The issue of a photograph being used as an anticipation was considered in Van der Lely NV v Bamfords Ltd (1963) RPC 61, where it was stated:

"If the photograph is to be held to prove anticipation it must be possible for that man to work from the photograph, and, without himself adding a scintilla of invention, to prepare the necessary drawings and ultimately by a process of trial and error to produce a workable machine which incorporates all the integers in the appellant's claim 1."

Secret Use​​​​​​​

Secret use occurs where there is a use of the claimed invention in Australia for commercial gain by or on behalf of the patentee, nominated person or their predecessor in title before the priority date of the claim.  The grounds of secret use is provided to stop a patentee from gaining an effective extension of patent term.

Secret use is not generally considered at examination. However, the issue may arise in cases where a third party has provided evidence of such use, for example the provision of material under s27, or during re-examination or opposition proceedings. In such cases, the issue of secret use may have a bearing on the assessment of novelty, as it concerns the use of the alleged invention before a priority date.

It is important to note that the grounds of secret use only applies where there has been commercial gain.  Use of the invention, that is non-commercial and secret, will not invalidate a patent claim. Examples of such non-commercial secret use include:

  • use for the purposes of reasonable trial or experimentation (that is, validating that the invention will work);
  • use occurring only during a confidential disclosure of the invention;
  • any use other than for the purpose of trade or commerce; and
  • use by or on behalf of the Commonwealth, a State, or a Territory where the patentee, or nominated person, or their predecessor in title to the invention has disclosed the invention, so far as claimed, to the Commonwealth, State, or Territory.

Relevant Case Law

Azuko Pty Ltd v Old Digger Pty Ltd (2001) FCA 1079 is the authoritative case on secret use in Australia. It discusses the meaning of ‘use’ at paragraph 183 and lays out the test for prohibited secret use at paragraph 181.

Confidential Information

Particular prior art information can be disregarded for the purposes of novelty and inventive step if the applicant can prove that the information was published without their consent. Suitable evidence that can be supplied by the applicant include Non-Disclosure Agreements (NDAs), confidentiality agreements, or other commercial in-confidence agreements produced by international working groups. Such evidence would prove that the cited information is considered confidential and should not have been published.

An applicant may choose to submit evidence of confidential information if the publication date was such that the Grace Period does not apply.

If an applicant provides such evidence in response to an objection, then the citation relied upon may not be prior art.  Examiners will need to consult with their supervisor to determine whether the citation is in fact part of the prior art base.

Amended Reasons

Amended Reason Date Amended

Published for prod

Published for testing

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