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. Construing a Citation

Date Published

Key Legislation:

Patents Act:

  • s7 Novelty, inventive step and innovative step  
  • s24 Validity not affected by making information available in certain circumstances
  • Schedule 1 Dictionary

Patents 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

Referenced Acts:

  • s2B Acts Interpretation Act

Construe As for Any Other Document

The rules of construction for citations are the same as those that apply to the construction of patent specifications. 

Examiners must determine the teaching of a citation by reading and interpreting the document as though they are the skilled addressee, using the common general knowledge in the art at the date of publication. Thus, examiners must endeavour to stand in the shoes of the addressee and give the citation a purposive construction, rather than a purely literal one.

Legal Principles and relevant case law

Populin v HB Nominees Pty Ltd (1982) 41 ALR 471 explains that the citation should be construed "not as a matter of abstract uninformed construction", but by making "a common-sense assessment" of what it would convey to the skilled reader in the context of the then-existing published knowledge. Thus, the citation should be given a purposive construction:

"A patent specification should be given a purposive construction rather than a purely literal one derived from applying to it the kind of meticulous verbal analysis in which lawyers are too often tempted by their training to indulge." From Catnic Components Ltd v Hill and Smith Ltd (1982) RPC 183 at page 243.

Date for Construing a Citation and using Common General Knowledge

For novelty

A citation is construed and read in the light of the common general knowledge as at its date of publication to the exclusion of information subsequently discovered. The question to be considered is how the person skilled in the art (PSA), at the time of publication, would interpret the prior document, and not what was in the mind of the author.

For inventive step

The citation is construed and read in the light of the common general knowledge by the PSA when trying to solve the problem, i.e. at the priority date of the claims being examined. This means that for the purposes of inventive step, the disclosure of a citation may be effectively extended by having regard to subsequent common general knowledge developed in the period between the publication date of the citation and the priority date of the claim under consideration.

Legal Principles and relevant case law

General Tire & Rubber Co. v Firestone Tyre & Rubber Co. Ltd (1972) RPC 457 at page 485 states that to assess whether a citation discloses each of the essential features of a claims, it must:

"be interpreted as at the date of its publication, having regard to the relevant surrounding circumstances which then existed, and without regard to subsequent events. The patentee's claim must similarly be construed as at its own date of publication having regard to the relevant surrounding circumstances then existing. If the earlier publication, so construed, discloses the same device as the device which the patentee by his claim, so construed, asserts that he has invented, the patentee's claim has been anticipated but not otherwise."

"Date of publication" in this context should be taken to mean the date of disclosure by filing of the subject matter claimed (see Ramset Fasteners (Aust) Pty Ltd v Advanced Building Systems Pty Ltd (1996) AIPC 91-226 at 37, 322; 34 (1996) IPR 256 at 267).

See also:

  • Bloch and Ilford Ld's Patent [1936] 53 RPC 92 at page 98, lines 14 to 16; and

  • Ore Concentration Company (1905) Ld v Sulphide Corporation Ld (1914) 31 RPC 206 at page 224.

Common General Knowledge

What is Common General Knowledge?

The type of information that can be considered common general knowledge differs depending on the technical field or industry of the invention. It is that knowledge which every worker in the art may be expected to have as part of their technical equipment. It consists of training, experience, observation and reading. While in a court situation the common general knowledge may be established by the direct evidence of a PSA, such advice is usually unavailable during examination.

Consequently, while in general examiners are not PSAs, their knowledge of common general knowledge and/or specific types of written information may be indicative of the common general knowledge in the first instance, when determining novelty or inventive step. Suitable written information may include:

  • standard texts and handbooks;
  • most dictionaries of standard English;
  • relevant technical dictionaries;
  • concession in the patent application under examination;
  • magazines or other publications specific to the art; and
  • patent specifications, under certain conditions.

However, the material disclosed in such publications does not necessarily constitute common general knowledge in the art. This depends on whether or not the information is generally known and accepted in the relevant field.

Assertion of Common General Knowledge

Where differences between the claimed features and those disclosed in the citation are standard or trivial, examiners at first instance, need only provide broad reasoning to support an assertion of common general knowledge (for example, the feature relates merely to well-known laboratory methods) without documentary evidence.

Note however that when responding at further report stage, depending on the evidence and argument supplied by the applicant, it may be appropriate to support further arguments on the nature of the common general knowledge by reference to the written material.

Reading "in the light of common general knowledge" is a process whereby the words and phrases used in a document are given the meaning that they would have had to a PSA at the relevant date. For example, "adhesive means" would be read in the light of the common general knowledge to be a reference to any adhesive that the PSA would have understood as appropriate.

This is not a process of using the common general knowledge to read mechanical, chemical, or other technical features into the citation which are not implicitly present. That process is one of adding common general knowledge. Examiners must not add common general knowledge to a citation to establish lack of novelty.

Legal Principles and relevant case law

For an explanation of what is common general knowledge, see Automatic Coil Winder Co. Ld v Taylor Electrical Instruments Ld (1944) 61 RPC 41 at page 43.

In Minnesota Mining & Manufacturing Co. v Beiersdorf (Australia) Limited (1980) 144 CLR 253 at page 292, Aickin J. stated:

"The notion of common general knowledge itself involves the use of that which is known or used by those in the relevant trade. It forms the background knowledge and experience which is available to all in the trade in considering the making of new products, or the making of improvements in old, and it must be treated as being used by an individual as a general body of knowledge."

This "notion of common general knowledge" has been expanded upon by some subsequent decisions as discussed below.

In ICI Chemicals & Polymers Ltd v Lubrizol Corp 45 IPR 577, Emmett J stated at paragraph 112:

"The common general knowledge is the technical background to the hypothetical skilled worker in the relevant art. It is not limited to material which might be memorised and retained at the front of the skilled workers mind but also includes material in the field in which he is working which he knows exists and to which he would refer as a matter of course. It might, for example, include:

  • standard texts and handbooks;
  • standard English dictionaries;
  • technical dictionaries relevant to the field;
  • magazines and other publications specific to the field."

In relation to the use of written material to determine what is common general knowledge, British Acoustic Films Ld v Nettlefold Productions (1936) 53 RPC 221 at page 250 states:

"In my judgement it is not sufficient to prove common general knowledge that a particular disclosure is made in an article, or a series of articles, in a scientific journal, no matter how wide the circulation of that journal may be, in the absence of any evidence that the disclosure is accepted generally by those who are engaged in the art to which the disclosure relates. A piece of particular knowledge as disclosed in a scientific paper does not become common general knowledge merely because it is widely read, and still less merely because it is widely circulated. Such a piece of knowledge only becomes common general knowledge when it is generally known and accepted without question by the bulk of those who are engaged in the particular art; in other words, when it becomes part of their common stock of knowledge relating to the art."


"It is certainly difficult to appreciate how the use of something which has in fact never been used in a particular art can ever be held to be common general knowledge in the art."

This was affirmed in General Tire & Rubber Company v Firestone Tyre and Rubber Company Ltd (1972) RPC 457, with the qualification that "without question" should read "generally regarded as a good basis for further action."

​​​​​​​In Bristol-Meyers Squibb Co. v F H Faulding & Co. Ltd 46 IPR 553 Black CJ and Lehane J stated at paragraph 30:

"If a patent application, lodged in Australia, refers to information derived from a number of prior publications referred to in the specification or, generally, to matters which are known, in our view the Court - or the Commissioner - would ordinarily proceed upon the basis that the knowledge thus described is, in the language of sec 7(2) of the 1990 Act, part of "the common general knowledge as it existed in the patent area". In other words, what is disclosed in such terms may be taken as an admission to that effect."

Note the requirement that common general knowledge be restricted to that which existed in Australia was removed from s.7 for standard patent applications with an examination request filed on or after 15th April 2013. However, the principle expressed in the above passage has not changed for such applications.

However, the occurrence of the word "ordinarily" should be noted in the above passage. Thus, each situation must be assessed on its merits, for example, Beissbarth GmbH v Snap-on Technologies Inc. (2001) APO 20 and BHP Steel (JLA) Pty Ltd v Nippon Steel Corporation (1999) APO 69.

In Aktiebolaget Hassle and Astra Pharmaceuticals Pty Limited v Alphapharm Pty Ltd 51 IPR 375 Wilcox, Merkel and Emmett JJ stated at paragraphs 71 - 74:

"71 While manufacturers' literature may well play an important role in the work of a hypothetical formulator, as Lehane J observed at para 42 [of the decision under appeal], in the light of the authorities it would be a "bold" submission to contend that material, which is not part of common general knowledge, can be relied upon to determine the question of obviousness. Nevertheless, by a process that his Honour characterised as taking the routine steps that the hypothetical formulator would take for the purpose of formulating a drug, such documents were held to be admissible for the purpose of raising "general ideas".

72 If that process were permissible, the concept of common general knowledge would lose much of its significance. If it is shown that the particular skilled worker in the field would, as a matter of routine, read literature beyond the common general knowledge of the field, the distinction becomes quite meaningless. The question is not whether a skilled worker conducting a literature search would find pieces from which there might have been selective elements which make up a patent - Minnesota Mining & Manufacturing Co v Beiersdorf (Australia) Ltd (1980) 144 CLR 253 at 293. What might be found by a diligent searcher is not the same as "common general knowledge".  

73 That is not to say that the whole of the content of "common general knowledge" need be within the conscious awareness of the hypothetical non-inventive skilled worker. For example, there may be publications of technical and detailed information that are habitually consulted by the hypothetical skilled worker. Notwithstanding that the hypothetical skilled worker would not have the whole of the contents of such reference material in his or her mind, such information should be regarded as part of common general knowledge.

74 Another area where it may be permissible to rely upon information that is not part of the common general knowledge is where the hypothetical addressee, faced with a problem, would resort to information that is fundamental to understanding the nature of the problem, if this were found to be a routine step that would have led from the prior art to the invention: cf Wellcome Foundation at 286 per Aickin J. Such information would include information about the basic characteristics of a drug for which a formulation is to be found."

This decision of the Full Federal Court was appealed to the High Court (Aktiebolaget Hassle v Alphapharm Pty Ltd (2002) HCA 59; (2002) 212 CLR 411), and in this aspect the High Court appeared to leave untouched the decision of the Federal Court. It merely stated:

"Their Honours correctly held, contrary to what had been decided by the trial judge, that it was impermissible to have regard to documents that would have been read merely for "general ideas".

For case law on the use of common general knowledge when construing a citation, and that adding common general knowledge to a citation is not permissible, see Acme Bedstead v Newlands (1937) 58 CLR 689:

"a given specification is not to be read in a vacuum. The reader must be regarded as having at least the common knowledge of the art."

"It is contended, however, that there is no justification for, to put it shortly, adding common general knowledge to an alleged paper anticipation and thus depriving a patent of subject matter."

Common General Knowledge not Limited to Australia

The common general knowledge that can be used in objections of lack of inventive step is not limited to just the common general knowledge in Australia, that is, there is no geographical limitation on the common general knowledge. Thus, a publication printed overseas can be relied on as indicative of the common general knowledge.

Likewise, what is admitted as common general knowledge in a specification prepared overseas can be taken to be common general knowledge.  It is the common general knowledge of the person skilled in the relevant art that is taken into consideration, not the knowledge of the person in a specific geographical location.

In the first instance, examiners should proceed on the basis that there is no difference (or no significant difference) in the common general knowledge of the PSAs in one country from that of their counterparts in another country. Arguments that a piece of knowledge known to PSAs in a particular geographical location is not common general knowledge are, in general, not to be accepted. This argument assumes the PSA in one geographical location is unaware of what is well-known to others working in the same art in another location.  This would suggest that the PSA in one location is disconnected from the world at large, which is unlikely in view of modern technology.

Nevertheless, such an argument may be supported by persuasive evidence. However, care must be taken to distinguish between situations where the knowledge is known to a small number of people and where the knowledge is generated by a small number of people. While a feature that is well-known to a few is not necessarily common general knowledge, it is equally true that common general knowledge is not necessarily defined by the number of people working in the art. For example, if information arises only from the research of a small number of people, that circumstance does not prohibit that information from being common general knowledge. The question is whether that information has become part of the technical background of the PSA.

Acknowledged Prior Art and Patent Specifications as Indicators of Common General Knowledge

Prior art can be acknowledged in a patent specification for various reasons such as to provide background to the problem being addressed and as a requirement of overseas jurisdictions. It is generally not an admission of common general knowledge in the field, unless it is made clear that it is.

Thus, the contents of individual patent specifications are not usually part of the common general knowledge of the field and in normal circumstances, examiners should not rely on a single patent specification to establish the state of the common general knowledge.

Where multiple specifications refer to a piece of knowledge, this may be indicative of that knowledge being common general knowledge, especially when the applications are by different applicants. However, examiners are not to conduct lengthy searches for the sole purpose of identifying common general knowledge, but instead should consider the possibility of combining documents where the PSA would be reasonably expected to have done so.

Legal Principles and relevant case law

General Tire & Rubber Company v Firestone Tyre and Rubber Company Ltd (1972) RPC 457 at page 482:

"... it is clear that individual patent specifications and their contents do not normally form part of the relevant common general knowledge."

However, as was stated in Minnesota Mining & Manufacturing Co. v Beiersdorf (Australia) Ltd (1980) 144 CLR 253 at page 294:

"There may be some fields of endeavour in which those who work therein study and make themselves familiar with all patent specifications as they become available for inspection in one or in many countries so that what was contained therein becomes common general knowledge in that particular trade or field of manufacture in the country in question. Examples are provided by Vidal Dyes Syndicate Ltd v Levinstein Ltd.** and British Celanese Ltd v Courtaulds Ltd.*"

** (1912) 29 RPC 245 at pages 279-280.

(1933) 50 RPC 259 at page 280.

Identifying the Person Skilled in the Art

The patent specification is written for the PSA. Therefore, the identity of the PSA is relevant to novelty, inventive step, sufficiency of description and claim construction. In some contexts, this hypothetical person is referred to as the skilled addressee, and although in some situations courts have found them to be slightly different people, for the purposes of examination, the PSA and the skilled addressee are interchangeable.

The PSA should be identified in light of the problem the claimed invention is directed to solving, and not in light of the claimed solution.

The PSA:

  • is a skilled but non-inventive worker in the relevant field of technology;

  • knows the common general knowledge in the art;

  • could be anyone from a tradesman in some arts to a highly qualified scientist in others depending on the nature of the problem; and

  • could be a team of people.

Identifying the PSA is dependent on the problem to be solved by the claimed invention. Thus, where the claimed solution is in an art remote from the identified problem, the art in which a novelty search is conducted will be different from the art of the PSA.  In these circumstances, examiners must decide:

  • whether the skilled person, while deemed to have been aware of and to have carefully read any documents located in the search, would have appreciated the relevance of those documents to the problem that the claimed invention seeks to solve; and
  • whether any documents would be considered a worthy starting point for further investigation or development.  

Thus, in certain situations it may not be possible to cite a document located during the novelty search for the purposes of inventive step.

Legal Principles and relevant case law

See, for example, Root Quality Pty Ltd v Root Control Technologies Pty Ltd 49 IPR 225American Cyanamid v Ethicon Ltd (1979) RPC 215 and Sunbeam Corp v Morphy-Richards (Aust) Pty Ltd (1961) ALJR 212.

For a discussion on the subtle distinction between the PSA and the skilled addressee, see The Skilled Addressee, Federal Judicial Scholarship, Justice Middleton.

Errors in the Citation

Where there is an error in a citation, that error is not to be given a literal interpretation. In particular:

  • if the skilled addressee would have recognised the error, but knew how to correct it, the corrected version is disclosed, but the original version is not;​​​​​​​

  • if the skilled addressee would have recognised the error, but not known how to rectify it, the matters relating to that error and its correction have not been disclosed; and

  • if the skilled addressee would not have recognised the error, the matters relating to that error have not been disclosed.

Thus, where the product of a method has been incorrectly identified:

  • a later claim to the incorrectly identified substance is novel; and

  • a later claim to the substance actually produced by the method is novel, unless there is evidence that the method has actually been used.​​​​​​​

Claims as a Disclosure

Where a citation is a patent specification, the claims of that specification may provide a relevant disclosure. In particular if a claim includes matter that is not in the description.

However, where the claim is in conflict or inconsistent with the description, the claim does not constitute a disclosure of that conflicting subject matter.

Furthermore, when considering the claims of a citation, examiners must be careful to distinguish between the scope of those claims, and the disclosure of the citation. In particular, the fact that something falls within the scope of a claim of a citation does not in itself mean that matter has been disclosed in the citation.

Thus, when considering patent specifications as citations, examiners should rely upon the claims of the citation only as an indication of the disclosures in the citation. A proper determination of the disclosure of the citation requires consideration of the specification as a whole.

Legal principles and relevant case law

For case law discussing relying on the claims of a patent specification for a relevant disclosure, see:

  • Monsanto Co's Application [1965] AOJP 3362 (when the claim is inconsistent with the description); and

  • Pugh v Riley Cycle Company Ld (1914) 31 RPC 266 at page 277).

Amended Reasons

Amended Reason Date Amended

Published for testing

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