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. Selections

Date Published

Key Legislation:

Patents Act:

  • s7(1) Novelty
  • s18(1)(b)(i) Patentable inventions
  • s24 Validity not affected by making information available in certain circumstance
  • s102 What amendments are not allowable?
  • s104 Amendments by applicants and patentees  
  • 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

General Disclosures and Selections

A broad, generic, vague and/or speculative disclosure cannot anticipate a narrow claim.

However, there are situations, particularly in the chemical field, where the disclosure of a citation is broad, and many molecular combinations can be claimed by altering substituent groups. Where a citation describes how to make particular combinations and asserts that the same properties will be common to the variants, it is possible that the earlier citation could be an enabling disclosure for the later, narrower claim.


  • where a specification provides instructions on making a compound, together with an indication that it has been made (for example, a melting temperature), there is a high presumption that the disclosure of the compound is an enabling disclosure which can deprive a later claim to that compound of novelty; and
  • the disclosure of a named chemical compound with no indication of it having been made, is nevertheless an enabling disclosure which can deprive a later claim to that compound of novelty, if it can be said that the production of that compound can be affected by any skilled chemist following the indications given; but
  • if the disclosure of a named chemical compound is not an enabling disclosure, it cannot deprive a later claim to that compound of novelty.

However, there exists a problem that some of the broadly claimed chemicals might have unexpected properties which a later researcher discovers and wants to patent. Therefore, the law regarding selection patents has been developed to deal with that problem and achieve two objectives. First, to protect the original invention; and second, to encourage other researchers to discover new advantages.

The following sections provide guidance on selection patents.

Selection Criteria

The question of "selection" arises when the invention claimed lies within a known field. Before an invention may be regarded as a selection, there must exist a single prior disclosure against which the claimed invention is compared. It is not necessary for the prior disclosure to encompass the entire claim under consideration. Only that portion of the claim which falls within the prior disclosure can have the selection test applied to it. Any portion of the claim which falls outside the prior disclosure is subject to the normal tests for lack of novelty and inventive step.

The following are criteria for a valid selection patent:

  • the selection must be based on some substantial advantage gained or some substantial disadvantage avoided;
  • the whole of the selected members must possess the advantage in question; and
  • the selection must be in respect of a quality of a special character which may fairly be said to be peculiar to the selected group.

A selection can arise irrespective of the breadth of the earlier disclosure of a parent class, or the manner of describing that class.

Selection Specification Must Describe Advantage

The specification must describe the advantage possessed by the selected members and upon which the selection is based.

Although specifications which are drafted in the first instance as a selection will usually have a clear statement of the advantages of the selection, this may not be the case where the draftsperson drafted the specification without knowledge of the parent class. This is particularly likely where a "whole of contents" objection is being considered. In certain circumstances, an amendment of the specification to describe the advantages may not be allowable under s.102.

Mere Choice Does Not Make a Selection

While it is immaterial whether a selection has been made consciously or not, examiners must be careful to distinguish between a patentable selection and a mere choice between alternatives. Whenever a range is specified, it is likely that some values will have better results than others. Finding the optimum values or verifying previous predictions does not constitute a selection. The advantage gained from the selection must be from the inventor’s own discovery and it must be unexpected.

Level of Disclosure in a Citation to Anticipate a Selection

​​​​​​​The basic level of disclosure required to anticipate a claim to a selection is the same as for any other claim. The law of selection operates to exclude an objection of lack of novelty in those circumstances where classes of compounds or items disclosed in a citation have not been made and consequently their properties are not known.


  • if the citation does not provide an enabling disclosure, there is no anticipation; and
  • if any of the selected compounds have actually been made previously, a claim to that selection lacks novelty.

If a claim is a valid selection, it will be novel over the relevant prior art. However, the mere fact that it is a selection does not render the claim inventive.  Examiners must still consider whether there is an inventive step in making the selection.

Mechanical or Electrical Selection

Although most of the cases referred to in this part relate to chemical inventions, the issue of selection is not confined to this technology.

See, for example:

Clyde Nail Co. Ld v Russell (1916) 33 RPC 291, which relates to an alleged mechanical invention that lies in the selection of a particular shape, which has certain advantages, of blank that is cut from a plain unribbed strip without waste; and

Bosch's Application (1909) 26 RPC 710, which relates to an alleged electrical invention. A patent may be granted for selecting the best material, the suitability of which was not previously known, for a particular purpose. However, in this particular case, it was found that the use of non-magnetisable steel (well known for being a non-magnetic material), for the same purpose, same place and same way as the prior art teaches to use a non-magnetisable material, is not novel or inventive.

Legal principles and relevant case law

In relation to Practical Utility, see Hill v Evans (1862) 6 LT 90:

"Whatever, therefore is essential to the invention must be read out of the prior publication. If specific details are necessary for the practical working and real utility of the alleged invention, they must be found substantially in the prior publication ... the prior knowledge of an invention to avoid a patent must be knowledge equal to that required to be given by a specification, namely, such knowledge as will enable the public to perceive the very discovery and to carry the invention into practical use."

Lord Westbury in Hill v Evans (1862) 6 LT 90, also provides early case law on the issue of disclosure:

"The antecedent statement must be such that a person of ordinary knowledge of the subject would at once perceive, understand and be able to apply the discovery without the necessity for further experiments."

Subsequent courts have interpreted this to mean that something less than a literal disclosure can act as an anticipation. Thus, Lord Reid in Van der Lely NV v Bamfords Ltd (1963) RPC 61, stated:

"Lord Westbury must have meant experiments with a view to discovering something not disclosed. He cannot have meant to refer to the ordinary methods of trial and error which involve no inventive step and are generally necessary in applying any discovery to produce a practical result."

The full Federal Court ruled in WR Grace and Co. v Asahi Kasei Kogyo Kabushiki Kaisha (1993) AIPC 90-974, that a "clear recommendation" could be a sufficient disclosure.

However, Nicaro Holdings v Martin Engineering 16 IPR 545 at page 563 makes it clear that the disclosure will not be an anticipation if the skilled addressee has to be inventive in applying the teaching of the earlier disclosure or in arriving at the essential integers of the claim:

"It follows from the English authorities as they have been applied in Australia that, whilst Hill v Evans (supra) does not require a literal disclosure and something less may suffice and whilst an alleged paper anticipation is to be treated as read by a skilled addressee, a disclosure will fall short of an anticipation by description of an effective means by which a combination claimed in the patent in suit might be produced, if what is required of the skilled addressee is the exercise of any inventive ingenuity..."

In relation to clear and unmistakable directions, General Tire & Rubber Co. v Firestone Tyre & Rubber Co Ltd (1972) RPC 457 at pages 485-486 states that:

"If carrying out the directions contained in the prior inventor's publication will inevitably result in something being made or done which, if the patentee's patent were valid, would constitute an infringement of the patentee's claim, this circumstance demonstrates that the patentee’s claim has in fact been anticipated.”

"To anticipate the patentee's claim, the prior publication must contain clear and unmistakable directions to do what the patentee claims to have invented ... A signpost, however clear, upon the road to the patentee's invention will not suffice. The prior inventor must be clearly shown to have planted his flag at the precise destination before the patentee."

"If ... the prior publication contains a direction which is capable of being carried out in a manner which would infringe the patentee's claim, but would be at least as likely to be carried out in a way that would not do so, the patentee's claim will not be anticipated."

Also, Canadian General Electric Co. Ltd v Fada Radio Ltd (1930) 47 RPC 69 at page 90 states:

"Any information as to the alleged invention given by any prior publication must be for the purpose of practical utility, equal to that given by the subsequent patent. The latter invention must be described in the earlier publication that is held to anticipate it, in order to sustain the defences of anticipation. Where the question is solely one of prior publication, it is not enough to prove that an apparatus described in an earlier specification could have been used to produce this or that result. It must also be shown that the specifications contain clear and unmistakable directions so to use it. It must be shown that the public have been so presented with the invention that it is out of the power of any subsequent person to claim the invention as his own."

In relation to enabling disclosures, Nicaro Holdings Pty Ltd v Martin Engineering Co. 16 IPR 545 at page 549 states:

"The prior art must enable the notional skilled addressee at once to perceive and understand and be able practically to apply the discovery without the necessity of making further experiments. Whatever is essential to the invention must be read out of or gleaned from the prior publication."

Similarly, in Acme Bedstead Co. Ltd v Newlands Bros Ltd (1937) 58 CLR 689, Dixon J referred to the:

"well-settled rule that a prior publication, giving information that does not become part of the common knowledge, does not invalidate a subsequent patent unless it supplies enough information to enable a person of proper skill in the art to produce the same mechanical device or appliance or carry out the process claimed in the later specification."

In Asahi Kasei Kogyo KK's Application [1991] RPC 485, the court held (citing Genentech Inc's (Human Growth Hormone) Patent [1989] RPC 613):

"to constitute an anticipation of a claim to a new chemical compound by a prior document, the disclosure in that prior document must be an enabling disclosure."

In relation to general disclosures and selections, it is stated in Hill v Evans (1862) 6 LT 90 that:

"Apparent generality or a proposition not true to its full extent will not prejudice a subsequent statement which is limited, accurate, and gives a specific rule of practical application .... the prior knowledge of an invention to avoid a patent must be knowledge equal to that required to be given by a patent, namely such knowledge as will enable the public to perceive the very discovery, and to carry the invention into practical use."

Thus, a generic formula which describes:

"Countless permutations and combinations of chemical formulae which could have been produced by a gorilla mindlessly producing chemical formulae with no knowledge of what they mean, nor whether any suggested formula was capable of manufacture."

This does not constitute a disclosure of any particular chemical within the generic formula ("the gorilla test" of Beecham Group Ltd. v Bristol Myers Co. 1 NZLR 192 at page 218).

The court in E.I. Du Pont de Nemours (Witsiepe's) Application [1982] FSR 303, considered the issue of an earlier citation disclosing many combinations by altering substituent groups (in the chemical field) and concluded that the earlier citation could be a disclosure for a later narrower claim:

"When a researcher is able to discover that a particular combination produces advantageous results he may well be able to assert, and will assert in the specification of his invention, that the same qualities will be produced by a number of variants or homologues described by a formula, or formulae. Moreover, having described how to produce the particular combination, he may well be able to assert, with truth, that production of any of the combinations can be made by any skilled chemist, following the indications he has given."


"... the fact that the product has not been made or tested may well be irrelevant, but different considerations arise when the issue is as to the field left open for subsequent researchers."

However, the court in E.I. Du Pont de Nemours (Witsiepe's) Application [1982] FSR 303 also recognized the problem that some of the broadly claimed chemicals might have unexpected properties which a later researcher discovers and want eto patent. The court suggested that the law regarding selection patents has been developed to deal with that problem:

"It has done so in the direction of recognising two objectives, first to protect the original inventor, as regards the invention which he has made, but secondly, to encourage other researchers in the field to use their inventive powers so as to discover fresh advantages and to treat the discovery of such advantages as inherent in selected members of the group or class as a patentable invention."

Note that submissions based on Beecham Group Ltd (New Zealand/Amoxycillin) Application [1982] FSR 181, to the effect that a novelty objection citing a compound can only be taken if it can be shown that the substance was actually made, are to be rejected. This case was in the context of selection patents and refers to the requirement from I.G. Farbenindustrie that none of the members of the selection were previously made (see the discussion in Genentech Inc's (Human Growth Hormone) Patent [1989] RPC 613 at pages 629 to 633 and E.I. Du Pont de Nemours & Co. (Witsiepe's) Application supra).

In Nicaro Holdings v Martin Engineering 16 IPR 545 at page 561, Gummow J stated:

"As is illustrated by the discussion of the English authorities by Falconer J in Genentech Inc's (Human Growth Hormone) Patent [1989] RPC 613 at pages 629 to 633, selection patents may require special attention, ..."

Gummow J raised the question of whether a different level of disclosure was required to anticipate a selection patent but did not elaborate on the issue. However, this has been considered by the English courts, as discussed below.

The matter of "selection" patents was considered in the case of I.G. Farbenindustrie A.G.'s Patents (1930) 47 RPC 289 and the criteria for a valid "selection" patent were stated at pages 322 to 323.

In E.I. Du Pont de Nemours & Co. (Witsiepe's) Application [1982] FSR 303, it was stated:

"In the first place, in order to leave open a field for selection by a subsequent inventor, it does not matter whether the original field is described by formula or by enumeration. A skilled chemist could, in most cases, quite easily transform the one into the other and the rights of the subsequent inventor cannot depend upon the notation used.

Secondly, the size of the initial group or class is not in itself decisive as to a question of prior publication of an invention related to a selected member or members. A selection patent might be claimed for one or several out of a class of 10 million ... or for one out of two."

The selection specification must describe the advantage of the selection. This is explained in Clyde Nail Company Ltd v Russell (1916) 33 RPC 291 at page 306: 

"A mere selection among possible alternatives is not subject matter. A selection to be patentable must be a selection in order to secure some advantage or avoid some disadvantage. It must be an adaptation of means to ends impossible without exercise of the inventive faculty. It follows that in describing and ascertaining the nature of an invention consisting in the selection between possible alternatives, the advantages to be gained, or the disadvantages to be avoided, ought to be referred to.”

Similar views were expressed in the case of I.G. Farbenindustrie A.G.'s Patents (1930) 47 RPC 289 at page 323:

"I must add a word on the subject of the drafting of the specification of such a patent. It should be obvious, after what I have said as to the essence of the inventive step, that it is necessary for the patentee to define in clear terms the nature of the characteristic which he alleges to be possessed by the selection for which he claims a monopoly. He has in truth disclosed no invention whatever if he merely says that the selected group possesses advantages. Apart altogether from the questions of what is called sufficiency, he must disclose an invention; he fails to do this in the case of a selection for special characteristics, if he does not adequately define them."

Ethyl Corporation (Cook's) Patent [1970] RPC 227 discusses Selection patents and the need to describe the advantage in the specification.

It is irrelevant whether the selection has been made consciously or not (Carpmael's Application (1929) 46 RPC 321), however the advantage of the selection should be unexpected (The Carlton Tyre Saving Co.'s Application [1973] AOJP 1404) and from the inventor’s own discovery (Apotex Pty Ltd (formerly GenRx Pty Ltd) v Sanofi-Aventis (2008) FCA 1194 at paragraph 86), or constitute a ‘quantum leap’ in relation to an earlier claimed advantage.

If any of the selected compounds have actually been made previously, a claim to that selection lacks novelty (I.G. Farbenindustrie AG's Patents (1930) 47 RPC 289).

Amended Reasons

Amended Reason Date Amended

Published for prod

Published for testing

Back to top