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Date Published


Section 40(3) requires the claims to be clear and succinct.

A claim might lack clarity if it is broad, the language is imprecise or there are spelling, grammar and formatting issues. However, this does not mean a claim requires precise and absolute terms in order to be clear. Claims are unclear when it is not possible to reasonably interpret them according to the rules of construction.

Claims do not need to be short, but they may lack succinctness if the length or number of claims makes it difficult to assess meaning and scope.

Examination practice

The claims are construed according to the rules of construction. Objections of lack of clarity arise when it is not possible to reasonably interpret the claims in accordance with said rules of construction.

See ‘Legal principles’ below for the main points of case law underlying the examination approach.

Examiners are to give consideration to whether a claim provides a reasonable basis by which a third party could, without difficulty, determine whether or not what they propose to do falls within the scope of the claim (that is, it provides 'a workable standard').  A claim will lack clarity if the standard specified by the terms of the claim would not permit a third party to determine whether an act would fall within the scope of the claim.

In assessing the clarity of the claims, examiners should generally focus on the independent claims and any dependent claims that appear to add significant features. By doing this, the examiner can focus on the clarity issues that most affect the overall scope of the monopoly.

Significant clarity issues, ones where the meaning and scope cannot be reasonably interpreted using the rules of construction, should be raised and pursued at all stages of examination.

Examiners should adopt a practical and common-sense approach, avoiding excessive proof-reading of the claims to identify each and every clarity issue.

However, in the interest of providing good customer service (and to benefit the public by providing a clear scope of monopoly at grant), examiners can decide to raise minor spelling errors or clarify ambiguities even if they do not significantly affect the scope or can be reasonably construed using the 'Rules of Construction'. These may be raised during as an objection, in an additional comment or in a phone conversation, whichever is the most appropriate. It is likely the most efficient stage to address these minor clarity issues during examination rather than it being resolved later on during Oppositions or before the Courts.

In later stages of examination trivial clarity issues like these need not be raised or pursued unless there are other substantial issues to be dealt with.

Where a clarity issue affects many claims within a specification (for example, as a result of poor translation), an objection based on a general observation can be made accompanied by an example.


Claims must be clear (s40(3)). Claims may not be clear if:

  • they use broad terms and language;

  • they use imprecise terms; or

  • there are spelling, grammar and formatting issues.

Broad terms and language

Broad terms and non-specific language can make a claim unclear.

Broad terms can create ambiguity or difficulty in determining the full scope of the claim. For example, a claim directed to ‘A handle for a tool’, the scope of ‘a tool’ is broad and encompasses a myriad of different possibilities ranging from a large mining drill to a small box cutter. This makes it difficult to determine the full scope of the claim. Where the examiner cannot readily resolve such ambiguities, an objection should be taken.

However, a claim is not necessarily unclear because it uses broad terms or language - in some cases, the nature of the invention justifies a broad monopoly. For example, a specific technical term or feature may be broad and cover a range of embodiments, but the overall scope of the claim is well-defined and can be readily determined by the reader (i.e. person skilled in the art). For example, the scope of terms such as ‘leaving group’ and ‘protecting group’ cover a range of embodiments, but the properties are well defined and understood in the chemical arts.

Imprecise terms

Claims may contain terms that are imprecise (for example, ‘about’, ‘substantially’, ‘approximately’, 'essentially'). These terms are acceptable if the Person Skilled in the Art (PSA) can determine whether what they propose to do would fall within the scope of the claim. This will depend on the facts of the case and should be a practical determination rather than a strictly literal one. It is acceptable if there is minor uncertainty at the edges of a claim.

For example, a claim contained the term "substantial effect as a cooling medium". Although, ‘substantial’ was considered imprecise, based on the facts of the case, it did not cause any ambiguity. It was determined the PSA would have little difficulty in determining when there was a "substantial" effect (Monsanto Company v Commissioner of Patents (1974) 48 ALJR 59), see also ‘Substantially’ and ‘about’.

Spelling, grammar and formatting defects

Spelling errors, poor grammar and formatting defects are only a concern when they hinder or prevent the reader from reasonably determining the scope of the claims. This may occur where, for example:

  • the error significantly alters the nature of a critical feature (for example, if ‘imino’ is misspelled ‘amino’; the chemical structure is changed);
  • the nature and/or frequency of the errors makes the claims difficult to construe (for example, successive dependent claims spell the same word differently and this makes it unclear which claims they append to); or
  • the errors reduce the readability of the claims to the extent that interpretation is hindered (for example, labels on diagrams are misaligned and it is unclear which points they refer to).


A claim must be succinct (s40(3)). Claims are not succinct if:

  • an individual claim is unnecessarily lengthy; or
  • the statement of claims as a whole is unnecessarily lengthy because it is repetitive.

There is no limitation on the length or number of claims in an application. Claims can be several pages long and still be acceptable. The issue is whether the length or number of claims makes it difficult to determine the meaning and scope. For this reason, succinctness may be considered a particular form of clarity.

For example, an application has 23 claims, all independent, each claiming various combinations of shared features. The number of independent claims itself is not an issue, but due to the intermingled combination of features, it is difficult to determine the scope of each claim and distinguish them from each other. Therefore, a lack of succinctness objection would be appropriate.

Note that there may be differences in approach between the various jurisdictions in which the applicant may be seeking protection. For example, in the US, multiple dependent claims cannot be dependent on other multiple dependant claims. This can result in a larger number of claims, but a lack of succinctness would not arise in AU.

Where different claims are directed to different combinations of integers, such that there is no common unifying inventive concept, the issue of clarity is limited to whether each of the claims can be properly construed. Such claims should be objected to on the basis of lack of unity (see Claims directed to a single invention).

Specific scenarios and claim types

Other issues that may affect the clarity of a claim include:

  • appended claims;

  • use of multiple sentences in a claim;

  • inclusion of redundant claims;

  • use of dictionary definitions;

  • use of cross-references;

  • inclusion of trademarks; and/or

  • use of disclaimers.

Appended claims

Appended claims can create issues if the examiner cannot determine the scope of the claim in accordance with the rules of construction (see Appendancies). In interpreting these claims, examiners should consider the substance and not the form of the appended claims.

Issues may arise when:


  • the appended claim adds features that are inconsistent with or contradictory to the claim it is appended to (that is, lack of antecedent)

For example, if claim 11 refers to ‘an apparatus as claimed in any one of claims 1 to 10 in which the condenser ...’, and none of claims 1 to 10 mention an apparatus that explicitly includes a condenser, claim 11 lacks clarity, as there is no antecedent for ‘the condenser’. An appropriate objection should be taken (see PERP codes [E50] and [E51]).

However, if some of claims 1 to 10 mention a condenser and some do not, the examiner can construe claim 11 as appended only to the claims that explicitly include a condenser. In this situation, in deciding whether to raise an objection, an examiner would consider the facts of the case and whether it would be in the best interests of the customer.

Similar lack of antecedent issues can also occur within a claim;​​​​​​​


  • a claim is dependent upon itself or to a non-existent claim

The appendancy in such cases is clearly an error. There is no issue if it is obvious which claim the appended claim is meant to be appended to. The examiner can simply add a construction note or additional comment to the report.

However, if the examiner cannot reasonably identify which claim it is meant to be appended to, the scope of the appended claim cannot be determined and an objection should be raised;


  • the appended claim extends beyond the scope of the claim it is appended to and does not include all the features of the invention of that claim 

For example, claim 1 refers to ‘product X’. A subsequent claim, claim 5, states, ‘Machine Y, which is able to produce product X according to claim 1’ but does not actually include the features of ‘product X’. Claim 5 is dealing with ‘Machine Y’, not ‘Product X’. Therefore, claim 5 is not truly appended to claim 1, and so care should be taken when construing the true scope of claim 5 (for further guidance on construing this type of appendancy see Claims That Do Not Import All Aspects of Parent Claim - Appendancies); and


  • a claim appends to a subsequent claim

Traditionally, claims are always appended to a numerically preceding claim. There is no legislative prohibition against a claim being drafted as appended to a subsequent claim. However, the chain of appendancy needs to be carefully examined to ensure that there are no circular loops in the chain of appendancy.​​​​​​​

More than one sentence

Claims are usually drafted as one sentence. However, claims can consist of more than one sentence, as long as it is clear from the wording of the claim that all the features of all the sentences must be read in combination.

Single-sentence claims comprising a number of separate paragraphs in list format (for example, i), ii), iii) or (a), (b), (c)) are also acceptable.

Redundant claims

A redundant claim is one that appears to have the same scope as another claim.

Even though a claim is redundant, it does not necessarily make the claim unclear, so no objection should be raised on this basis alone. However, examiners should follow the rule of construction that there is ‘a presumption against redundancy’. This means that, where a claim appears to be redundant, if it is possible to interpret it as different in scope from the others, we should do so (see A Presumption is Made Against Redundancy).

Dictionary definitions

A specification may state that it defines a word or phrase in a particular way. If that term or phrase is then used in the claims, the ‘dictionary definition’ (i.e. the definition indicated in the specification) is necessarily an element of the claims. Therefore, if there is a lack of clarity in that definition, there is a lack of clarity in the claims (see Dictionary principle).


Where a claim has a reference to matter contained in another specification (Australian or otherwise) or other document that may be amended over time (such as a GenBank entry or a webpage), that claim will not be clear unless the actual matter in question has been incorporated into the specification containing the claim.  This is because the wording of any such reference may be subject to change by amendment at any time, without the constraints of sec102 applying.

However, where a claim has a cross-reference to a recognised national or international standard (for example, AS, ASTM, IEEE), such reference does not give rise to a lack of clarity (see also PCT International Search and Preliminary Examination Guidelines [Part II] Chapter 4, paragraph 4.24).

Special considerations apply to applications for patents of addition that cross-reference the parent (see 5.6.11 Patents of Addition, ‘Issues specific to the Examination of additional applications’).


In the exceedingly rare situation where the applicant wishes to maintain a cross-reference to another specification (and the application is not for a patent of addition) or other document, relevant considerations are:

  1. is the content of the cross-reference permanently fixed? If not, the scope of the claim will be unclear for being indeterminate over time.
  2. is the cross-reference readily available? If not, the scope of the claim will be unclear due to an inability to ascertain the content of the cross-reference.

Note that where claims define an invention by cross-referencing to another document and this makes the claims unclear, the specification may also lack a clear enough and complete enough disclosure of the claimed invention and the claims may lack support, or for applications where the Act pre-Raising the Bar 2012 is applicable, fair basis. 

Trade marks in claims

A trade mark or proprietary name is used to identify the source of a good, not its properties. When a trade mark or proprietary name is used in a claim, the scope of a claim may be uncertain or ambiguous because the product sold under the trade mark may differ depending on region or time (for example, the composition of a laundry detergent may differ because of differences in local water hardness).

However, in some cases, trade marks can be used. For example, the use of ‘Bluetooth®’ does not cause ambiguity because the properties of Bluetooth are publicly available and standardised.​​​​​​​

Note that if a claim refers to a trade mark, it is highly likely that the trade mark will also be mentioned in the description of the invention. In this case, an objection of lack of clear enough and complete enough disclosure may also be relevant (see Claims are Clear and Succinct) or for applications where the Act pre-Raising the Bar 2012 is applicable, full description.


The specification may contain a disclaimer; a statement, separate from the claims (usually just before the claim pages), declaring that certain matter is to be excluded from them. The words "subject to the foregoing disclaimer" may be present in the preamble to the claims, however the absence of these words is not objectionable. This differs from a proviso, where the matter to be excluded is specified within the text of a claim.

Both disclaimers and provisos are commonly used to distinguish a generic invention from the prior publication of a particular entity that falls within the scope of the generic invention.

The existence of a disclaimer should be clearly indicated, similar to the situation where a ‘dictionary definition’ of a term is being relied upon. As a disclaimer modifies the scope of the claims, any lack of clarity in a disclaimer must be reported on as a lack of clarity in the claims.

See British Celanese Ltd. v Courtaulds Ltd. (1933) 50 RPC 259 at pages 273 to 284.

Where a disclaimer or proviso makes reference to another patent specification or other document which may be amended over time (such as a GenBank entry or a webpage), the general considerations in relation to references apply (see Clear and complete enough disclosure​​​​​​​, s40(2)(a), and Cross-References above).

Legal principles

Imprecise terms

The judgement in Flexible Steel Lacing Company v Beltreco Ltd (2000) FCA 890; (2000) IPR 331, cited with approval in Austal Ships Sales Pty Ltd v Stena Rederi Aktiebolag (2008) FCAFC 121; (2008) 77 IPR 229, stated:

"Lack of precise definition in claims is not fatal to their validity, so long as they provide a workable standard suitable to their intended use. The consideration is whether, on any reasonable view, the claim has meaning. In determining this, the expression in question must be understood in a practical, common sense manner. Absurd constructions should be avoided and mere technicalities should not defeat the grant of protection."

With regard to what constitutes ‘a workable standard’, consideration should be given to whether a claim provides a reasonable basis by which a third party could, without difficulty, determine whether what he/she proposes to do falls within the scope of the claim. A claim lacks clarity if a third party could not ascertain whether an act would fall within the scope of the claim (see Monsanto Co. v Commissioner of Patents (1974) 48 ALJR 59 at page 60).

In Monsanto Company v Commissioner of Patents (1974) 48 ALJR 59 the term ‘substantial effect as a cooling medium’ was used. The court found that, although ‘substantial’ is imprecise, in the facts of the case it did not cause any ambiguity. The judge found that those skilled in the art would have little difficulty in determining when there was a ‘substantial’ effect.

Similarly, in Catnic Components Ltd v Hill & Smith Ltd (1982) RPC 183 the term ‘vertical’, in the context used in the specification, did not mean exactly vertical.

By contrast, in Shell Internationale Research Maatschappij N.V. v Monsanto Co. (1968) AOJP 2397 the term ‘predetermined’ was used to qualify ‘amount’. The court found that the specification provided no means of determining the amount and there was no evidence that it could be determined as a matter of routine. In this circumstance the claim was not clear.

It is acceptable if there is minor uncertainty at the edges of a claim:

"The court will give little weight to puzzles which may arise ‘at the edge of the claim’ if those puzzles would not, as a practical matter, cause difficulty for the skilled addressee or manufacturer wishing to satisfy himself that what he proposes to do will not infringe that patent."

(Glaverbel SA v British Coal Corp (1994) RPC 443 at page 495.)


The principal judicial authority on succinctness is Bancroft’s Application [1906] 23 RPC 89. In that case there were 23 claims, all independent, claiming various combinations of features:

"We by no means desire to lay it down that the mere number of claims amounts to {lack of succinctness}, for a specification may be such that there are a great many claims, separate in their nature, which are justifiably made …. So long as the statement of each claim is in itself clear and succinct, and so long as there is an absence of repetition in the separate claims, we do not think that {a great many claims gives rise to lack of succinctness}."

The only Australian judicial precedent on the meaning or scope of the term ‘succinct’ as used in s.40 is in the lower court judgement in Doric Products Pty Ltd v Lockwood Security Products Pty Ltd (2001) FCA 1877:

"I accept that it takes patience, time and effort to unravel all of the claims of the Patent. Subject to the expenditure of that time and effort, there is no alleged ambiguity in the claims. The problem is not with prolixity, but with attempted compression, and the multitude of claims. That, however, falls short of establishing that the claim or claims are not clear and succinct."

The issue has arisen in hearings before the Commissioner, as follows:

  • ‘The application suffers from “an overdose of claims”’. The statement of claims is ‘eminently perplexing to the public.’ Nomad v Heyring (1992) APO 15;
  • ‘Inclusion of an inessential feature does not make a claim “non-succinct”.’ Tropical Export Nursery v Shade Span Industry (1994) APO 62;
  • ‘It is the right of an applicant to draft his claims so as to protect every aspect of the invention that he has disclosed. This can lead to a large number of claims, and potentially even a large number of independent claims. Whether such a drafting style results in claims that are not clear and succinct is a question of degree, that can only be decided by having regard to the specific claims and the specific description, rather than simply counting the number of claims.’ American National Can v Trigon (1996) APO 23; and
  • ‘it has long been accepted that claims will not be clear and succinct if their repetitious nature is such the difference in scope between two or more claims is not readily apparent, (see Bancroft’s Application [1906] 23 RPC 89). This situation rarely arises in practice but I think the present application is one such case because of the large number of different combinations of features claimed and the wide variety and ambiguity of the different terminology in the claims that is said to define the same key features. … Consequently I find, in addition to the matters of clarity discussed above, that the claims as a whole are not clear and succinct.’ Sabre v Amadeus Global Travel (2004) APO 21.

Note that decisions almost always refer to succinctness together with clarity, indicating that succinctness may best be considered as a particular form of clarity.

More than one sentence

In Leonard’s Application [1966] RPC 269 the court stated that although one-sentence claims are highly desirable, this may not be enforceable in all instances. A claim in the form of disjunctive sentences was held to be ambiguous and not allowable. However, an amended claim in 9 sentences was ultimately allowed.


See British Celanese Ltd v Courtaulds Ltd (1933) 50 RPC 259 at pages 273 - 284.

Amended Reasons

Amended Reason Date Amended

Published for testing

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