With the advent of claim fees in 2022, applicants must now limit the number of claims in their Canadian patent applications to avoid government fees. While cancelling claims (particularly dependent claims) is the simplest approach, many applicants prefer to condense claim sets, incorporating elements of several claims into a single claim by describing claim elements as exemplary or optional. This article explores the legal and practical consequences of such amendments.
Table of contents
1. Summary
4. “Exemplary” versus “optional” features—a material distinction
5. The term “optionally” can be essential claim language!
6. The position of the Canadian Intellectual Property Office (CIPO)
7. Practice in other jurisdictions
8. Should Canadian patent applicants use exemplary or optional claim language?
9. Conclusion
1. Summary
The following is a summary of key points and recommendations discussed in greater detail in this article:
- With a view to avoiding excess claim fees that must be paid when examination is requested, applicants now routinely file a reduced or condensed set of claims together with the examination request and fee. Although applicants may simply cancel some claims, a common practice is instead to incorporate features of those claims into other claims, specifying that they are exemplary or optional, thereby reducing the total number of claims.
- “Exemplary” (i.e. illustrative) claim features that are specific examples of species falling within a previously recited genus are distinct from “optional” claim elements, which may be present or entirely absent.
- In contrast to exemplary claim features, there are instances in which use of the term “optionally” is essential for properly defining the scope of patent claims. This arises most often in the context of chemical patent claim drafting and closed-ended claims.
- The Canadian Intellectual Property Office (CIPO) takes the position that exemplary claim language may be objectionable, and patent examiners routinely object to such language during prosecution. CIPO does not provide specific guidance on optional claim language. The ultimate legal question is whether the claims are sufficiently clear as to allow others to understand what would constitute infringement.
- The stated policy of the European Patent Office (EPO) is to treat exemplary and optional features as non-limiting and therefore objects only where a claim is internally inconsistent, e.g. an exemplary feature in fact is not a member of the claimed genus.
- The United States Patent and Trademark Office (USPTO) provides more detailed guidance, both for exemplary and optional features. Like CIPO, the USPTO states that exemplary claim language may render a claim indefinite. But most of the examples of indefinite exemplary claim language given by the USPTO do not involve a simple genus/species relationship, and the terminology could be indefinite for other reasons. Specific examples are given where optional claim language was found clear and definite.
- A claim in a Canadian patent must not be indefinite—it must inform the public as to what does or does not infringe the patent. Further, there is a single construction of a patent claim that applies for both validity and infringement. Accordingly, the patentee may have no choice but to concur that exemplary or optional features are not limiting, suggesting they have limited value absent special circumstances (e.g. certain elements of chemical patent claims or closed-ended claims).
- CIPO routinely objects to exemplary or optional features during prosecution. Possibly the applicant could overcome such objections with arguments that such features are clearly non-limiting. This can prolong prosecution, possibly requiring a request for continued examination (RCE) and fee.
- If the claims grant containing exemplary or optional features, a defendant might assert in litigation that such features render the claims indefinite. The patentee presumably would need to take the position that the features are clearly non-limiting, again calling into question their value in the first place.
- The alternative to exemplary or optional claim language is to include such features in separate (typically dependent) claims, where they carry patentable weight. The validity of each claim in a Canadian patent is assessed separately, and a patent containing both valid and invalid claims is given effect as if it contained only the valid claims. Moreover, including features in dependent claims can help ensure that claims from which such claims depend are interpreted as encompassing at least the subject matter of the dependent claims.
- When requesting examination of a Canadian patent application, applicants should consider whether they wish to include exemplary or optional elements in the claims, omit those elements entirely, make those elements essential, or pay excess claim fees and retain separate claims reciting such features if they are considered to be of sufficient importance.
2. Excess claim fees
No claim fees are payable at the time of filing a Canadian patent application or on entry of a PCT application into the Canadian national phase.
Rather, claim fees may first become payable when examination is requested.1 The examination request is due four years after the Canadian (PCT) filing date or three months after the presentation date of a divisional application, if that date is later than four years from the effective filing date of the divisional application.
An official fee of CAD $114.84 (2025 CIPO fee schedule) is payable for each claim in excess of 20 that is pending when examination is requested. There are no claim fees for excess independent claims, or for multiply dependent claims. Moreover, multiply dependent claims may depend from other multiply dependent claims.
Additional claim fees are payable with the issue fee based on the greatest number of claims in excess of 20 pending at any time after examination was requested and for which excess claim fees were not paid when examination was requested.
It is therefore a common practice to file an amendment with the request for examination, reducing the number of claims, often incorporating exemplary or optional features into the claims as a strategy to reduce the total number of claims.
3. Model claim set
The following model claim set is provided to illustrate common amendment strategies for reducing claim sets to avoid claim fees.
1-19. (not shown)
20. A process, comprising the steps of:
21. The process of claim 20, further comprising the step:
(e) applying a coating to the tablet.
22. The process of claim 20 or 21, wherein step (c) comprises heating the mixture to a temperature in the range of 80-85°C.
23. The process of any one of claims 20-22, wherein the diluent comprises one or more of methanol, ethanol, and 1-propanol.
24. The process of claim 21, wherein the coating is an enteric coating.
Avoiding the excess claim fees for the four claims above 20, the subject-matter of claims 21-24 can be condensed into claim 20 as optional or exemplary features:
20. A process, comprising the steps of:
(a) combining compounds X and Y to form a mixture;
(b) adding to the mixture 0.5-1.0 wt.%, based on the total weight of the mixture, of a diluent of the formula ROH, wherein R is benzyl or optionally substituted C1-C6 alkyl, for example, methanol, ethanol, and/or 1-propanol;
(c) heating the mixture to a temperature in the range of 70-90°C, preferably 80-85°C;
(d) pressing at least a portion of the mixture to form a tablet; and
optionally, a further step (e) applying a coating, such as an enteric coating, to the tablet.
4. “Exemplary” versus “optional” features—a material distinction
When describing patent claim terminology, “exemplary” means “serving as an example” or “illustrative” rather than “commendable” or “deserving imitation.” In the claims above, the expressions “for example,” “preferably” and “such as,” are used as exemplary claim terminology, providing specific illustrative examples of the immediately preceding claim element. The broader claim element is present as an essential feature of the claim (e.g. adding a diluent), whereas the exemplary claim language (the diluent comprises methanol, ethanol, or 1-propanol) merely describes instances of suitable diluents encompassed by the broader term.
In contrast, the term “optionally” may introduce an entirely new feature, rather than provide examples of an essential claim element. In the above claim set, the step (e), applying a coating to the tablet, was originally the subject of a dependent claim and then condensed into the independent claim, the term “optionally” clarifying that the tablet coating step may or may not be present. Similar to the exemplary embodiments described above, the entire (optional) step could be deleted from the independent claim, and the claim with the open-ended transitional expression “comprising” could still be infringed by a process including the coating step.
5. The term “optionally” can be essential claim language!
In some contexts, the distinction between exemplary and optional claim language can be critical. Although exemplary claim language probably can be deleted without changing the scope of a claim, in some instances, deleting the term “optionally” may significantly change the meaning of the claim.
Chemical patent claims
The expression “benzyl or optionally substituted C1-C6 alkyl” in the above claim set is an example. Patent applications typically contemplate chemical groups encompassing carbon chains in which a hydrogen atom is replaced (“substituted”) with another atom or group. Sometimes such substitutions are permitted, but in other cases the patentee may wish to exclude substitutions. Conventionally, this is set out unambiguously in the claims and the patentee may use an expression such as “benzyl or optionally substituted C1-C6 alkyl” to clarify that both substituted and unsubstituted alkyl groups are intended. Deleting “optionally” would exclude unsubstituted alkyl groups, and deleting “optionally substituted” could leave it unclear whether substitutions are permitted. In this context, “optionally substituted” unambiguously encompasses the both alternatives, and could also be written as “substituted or unsubstituted C1-C6 alkyl.”
One reason the term “optional” is so important in chemical patent drafting concerns the use of the term “comprises” or “comprising,” customarily understood to be an open-ended term meaning “including at least.” Illustrative original claim 20 above, including the transitional expression “comprising,” would commonly be understood to be open to the inclusion of additional steps, such that infringement would not be avoided by practicing the additional step (e) of applying a coating to the tablet, first recited in a dependent claim. In contrast, in the claim element “a diluent of the formula ROH, wherein R is benzyl or optionally substituted C1-C6 alkyl,” the term “is” excludes other options for R. This is an important convention in chemical patent claims because the phrasing “…wherein R comprises benzyl or optionally substituted C1-C6 alkyl” would be meaningless, the open-ended term “comprises” leaving R essentially unlimited and undefined.
Closed-ended claims
Another instance in which the term “optionally” could be critical is where the claim is intended to be closed to the inclusion of additional elements, typically indicated through use of the transitional expression “consisting of.” This is usually only done if the claim must distinguish over the prior art by the absence of prior art feature. If a particular additional element or step is to be encompassed by the claim, it likely must be introduced at first instance as an “optional” element or step. In the above example, if the claim preamble read “A process, consisting of the steps of…,” it would be necessary to include step (e) of coating the tablet as an optional step in the independent claim to ensure that it is not excluded.
6. The position of the Canadian Intellectual Property Office (CIPO)
CIPO’s Manual of Patent Office Practice (MOPOP) enumerates some expressions considered to be “imprecise,” including: "such as,” "or the like," "for example," and "preferably." The MOPOP states that the inclusion of any of these terms in a claim raises “a possibility” that the claim may not satisfy the requirements of subsection 27(4) of the Patent Act or section 60 of the Patent Rules.2 But, in practice, CIPO almost invariably objects to such terminology.
Notably, use of the term “optionally” is not specifically addressed in the MOPOP, but it too often attracts objections.
The usual objection made is that exemplary or possibly optional claim language is unclear, contravening subsection 27(4) of the Patent Act, which provides that “The specification must end with a claim or claims defining distinctly and in explicit terms the subject-matter of the invention for which an exclusive privilege or property is claimed.” The Canadian courts have characterized the requirement for compliance with subsection 27(4) of the Patent Act as requiring that the claims be sufficiently clear as to allow others to understand what would constitute infringement.3
A typical rejection raised in prosecution reads as follows:
Claims [….] are indefinite and do not comply with subsection 27(4) of the Patent Act. The use of the subjective expression “preferably”, appears to direct the claims simultaneously to both broad and narrow embodiments, causing a lack of clarity as to the intended scope of these claims.
There are two aspects to this rejection. First, the term “preferably” is considered subjective—what is “preferred” may be a matter of opinion. At least this aspect of the rejection could be avoided by using “for example,” or “such as.” The second aspect of the rejection is more fundamental—does the term “preferably” limit the scope of the claim?
While many objections raised under subsection 27(4) of the Patent Act are to claim terms that, although generic or broad, are not unclear, and thus more properly objections to the breadth of a claim rather than its clarity, the objection to exemplary claim language may go more properly to the heart of the matter—what does or does not infringe?
7. Practice in other jurisdictions
The European Patent Office (EPO)
The EPO addresses the various types of terminology discussed above under the single rubric “optional features,” stating in the Guidelines for Examination in the EPO:
Optional features, i.e. features preceded by expressions such as "preferably", "for example", "such as" or "more particularly" are allowed if they do not introduce ambiguity. In such a case, they are to be regarded as entirely optional.
These expressions introduce ambiguity and render the scope of the claim unclear if they do not lead to a restriction of the subject-matter of the claim.
For example, the wording "a method to manufacture an artificial stone, such as a clay brick" does not fulfil the requirements of Art. 84 because a clay brick will never be an artificial stone. Hence, it is unclear if either an artificial stone or a clay brick is manufactured by the method of the claim.
Similarly, the wording "the solution is heated up to between 65 and 85°C, particularly to 90°C" does not fulfil the requirements of Art. 84 because the temperature after the term "particularly" contradicts the range before it.4
It thus appears that the EPO simply disregards such features as non-limiting and therefore irrelevant to examination, an objection being raised only if the features are effectively non-sensical because they do not represent proper examples of species falling within the genus they purportedly exemplify.
The United States Patent and Trademark Office (USPTO)
The position of the USPTO in its Manual of Patent Examining Procedure (MPEP) appears less definitive than the position taken by the EPO:
Description of examples or preferences is properly set forth in the specification rather than the claims. If stated in the claims, examples and preferences may lead to confusion over the intended scope of a claim. In those instances where it is not clear whether the claimed narrower range is a limitation, a rejection under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph should be made. The examiner should analyze whether the metes and bounds of the claim are clearly set forth. Note that the mere use of the phrase “such as” or “for example" in a claim does not by itself render the claim indefinite.
Examples of claim language which have been held to be indefinite because the intended scope of the claim was unclear are:
(A) “R is halogen, for example, chlorine;”
(B) “material such as rock wool or asbestos” Ex parte Hall, 83 USPQ 38 (Bd. App. 1949);
(C) “lighter hydrocarbons, such, for example, as the vapors or gas produced” Ex parte Hasche, 86 USPQ 481 (Bd. App. 1949);
(D) “normal operating conditions such as while in the container of a proportioner” Ex parte Steigerwald, 131 USPQ 74 (Bd. App. 1961); and
(E) “coke, brick, or like material”. Ex parte Caldwell, 1906 C.D. 58 (Comm’r Pat. 1906).
The above examples of claim language which have been held to be indefinite are fact specific and should not be applied as per se rules. See MPEP § 2173.02 for guidance regarding when it is appropriate to make a rejection under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph.5
While stating at the outset that exemplary terminology including “such as” and “for example” does not by itself render a claim indefinite, the MPEP then goes on to cite instances in which such language was indeed found indefinite, concluding that there is no per se rule, and each case turns on its own facts. In not assuming that exemplary claim language is always non-limiting but may give rise to indefiniteness, the position taken in the MPEP is similar to that set out in the Canadian MOPOP.
But, notably, without delving into the details of the cases, only example (A) given in the MPEP appears to be an example of purely exemplary claim language that could have an unambiguous meaning. Chlorine is a halogen, a broader and definite known class of compounds that includes chlorine as a species. Irrespective of whether chlorine is mentioned, the skilled reader understands the meaning of the term “halogen.” Chlorine is an example of the known class of halogens just as “K” is one of the 26 letters of the alphabet or “19” is an example of a prime number. Unfortunately, the MPEP does not explain why example (A) is indefinite or give a case citation.
In contrast, each of remaining examples (B) – (E) in the MPEP does not define the broader general class so clearly. For instance, in example (B), “rock wool” and “asbestos” are indeed “materials,” but what are the metes and bounds of the broader class of materials? Fire-proof materials? Insulating materials? Similarly, in example (E), what are the common properties of “coke” and “brick” that define the scope of “other like materials”? As coke is a fuel and bricks are inert and non-flammable, it is difficult to see what common properties these materials share.
The MPEP separately addresses the term “optionally” in a discussion of “alternative” claim limitations, citing cases in which “optionally” was found acceptable:
Another alternative format which requires some analysis before concluding whether or not the language is indefinite involves the use of the term “optionally.” In Ex parte Cordova, 10 USPQ2d 1949 (Bd. Pat. App. & Inter. 1989) the language “containing A, B, and optionally C” was considered acceptable alternative language because there was no ambiguity as to which alternatives are covered by the claim. A similar holding was reached with regard to the term “optionally” in Ex parte Wu, 10 USPQ2d 2031 (Bd. Pat. App. & Inter. 1989). In the instance where the list of potential alternatives can vary and ambiguity arises, then it is proper to make a rejection under 35 U.S.C. 112(b) and explain why there is confusion.6
8. Should Canadian patent applicants use exemplary or optional claim language?
What does the applicant intend by the exemplary or optional language?
In assessing whether applicants should include exemplary or optional claim language, the first question to ask is what is the applicant’s purpose in doing so? Surely, the applicant’s intent is that the exemplary or optional features are non-essential or non-limiting. Otherwise, using the earlier example, an unambiguously narrowed claim would be written as follows:
20. A process, comprising the steps of:
(a) combining compounds X and Y to form a mixture;
(b) adding to the mixture 0.5-1.0 wt.%, based on the total weight of the mixture, of a diluent comprising one or more of methanol, ethanol, and 1-propanol;
(c) heating the mixture to a temperature in the range of 80-85°C,
(d) pressing at least a portion of the mixture to form a tablet; and
(e) applying an enteric coating to the tablet.
Indeed, the applicant cannot have it both ways, with a claim admitting to both a broad and narrow construction, as that would violate the fundamental precept that the claims must inform the public as to what does or does not infringe the patent.
Moreover, “[t]he same construction of a patent applies for purposes of both infringement and validity.”7 If the patentee takes the position that claim 20 (when containing exemplary features) reciting in step (c) “heating the mixture to a temperature in the range of 70-90°C, preferably 80-85°C” is novel over prior art teaching heating the mixture to 75°C (i.e. the narrower, preferred range is a claim limitation), then the claim cannot at the same time be infringed by a competitor practicing the process where the mixture is heated to 75°C (i.e. the narrower, preferred range is not a claim limitation). A more difficult construction issue arises when the prior art teaches heating to 75°C and the putative infringer practices the heating step at 80°C. Can the patentee rely on the narrower, preferred range to preserve the validity of the claim and capture the infringement? The situation would be much clearer (to the patentee’s benefit) if the narrower range were set forth in a separate dependent claim.
Practice before CIPO
If an Examiner were to raise a clarity objection to exemplary optional claim elements (as is common practice), the applicant could: (1) traverse the rejection; (2) make the exemplary claim language essential; (3) delete the exemplary claim language; or (4) move the exemplary subject matter to a new dependent claim.
Assuming the applicant concedes that the claim cannot be both broad and narrow at the same time, and the exemplary claim features are non-limiting, only option (4) gives the applicant the benefit of a claim in which the exemplary features carry patentable weight without narrowing claim scope, albeit at the cost of excess fees payable with the issue fee. Largely, including exemplary or optional features when filing a condensed claim set at the time examination is requested merely defers the harder decision of whether such features are of enough importance to justify additional claims and excess claim fees.
In addition, including claim features that may attract objections from CIPO can result in protracted prosecution and increased costs. A request for continued examination (RCE) must be made and an associated official fee8 paid for the applicant to respond to a third Examiner’s Report.
Validity of granted claims reciting exemplary or optional features
If the Examiner does not object to exemplary or optional claim features, or objections are raised but overcome, and the claims issue with those features, would the claims be valid? A defendant in an infringement action might argue that it is unclear whether the exemplary or optional features are indeed limitations, such that the scope of claims cannot be determined, and they therefore fail to comply with subsection 27(4) of the Patent Act. Given that compliance with subsection 27(4) of the Patent Act requires that the claims inform the public what constitutes infringement, and the principle that there is a single claim construction for both infringement and validity, it seems the patentee would have no option but to argue that the exemplary or optional claim features are just that, i.e. clearly non-limiting.
Are there any benefits to exemplary or optional claim features?
Assuming the patentee “cannot have its cake and eat it too,” and rely on both broad and narrow claim interpretations, there appear to be few benefits to exemplary or optional claim limitations, outside special circumstances (e.g. chemical patent drafting and closed-ended claims) as described above.
If CIPO agrees (and possibly a court in later litigation) that the exemplary or optional features are just that, and non-limiting, then they reflect subject-matter that can instead be described in the specification. Using the examples above, the specification could (and no doubt would) describe methanol, ethanol, and/or 1-propanol as suitable diluents. Indeed, as discussed above, the position of the USPTO as set forth in the MPEP is that description of examples or preferences is properly set forth in the specification (the “description” in Canadian terminology) rather than in the claims. Thus, even if including the examples in the claims helps clarify that the generic claim terminology must at least include these examples, this is already explained in the specification.
In contrast, there are clear benefits to including additional dependent claims, though of course at the cost of excess claim fees.
First, section 58 of the Patent Act provides that a patent may contain both valid and invalid claims, and in any proceeding concerning the patent, it is given effect as if it contained only the valid claims.9 Thus, an independent claim could be found overly broad and invalid, but a narrower dependent claim found both valid and infringed.
Second, even if it were not already abundantly clear from the specification, the inclusion of features in dependent claims further clarifies that a broadly defined feature in an independent claim includes at least the more specific examples recited in the dependent claim. See e.g. Halford v. Seed Hawk Inc.:“[An] independent claim cannot be given a construction which is inconsistent with the claims which are dependent on it.”10
Third, the principle of claim differentiation suggests that the inclusion of a selected embodiment in a dependent claim further clarifies that a broadly defined feature in an independent claim includes more than just the selected embodiment.
For the sake of completeness, it is noted that the Patent Act was recently amended to provide that written communications between the applicant and CIPO during prosecution of a patent application may be admitted into evidence during litigation of the patent to rebut any representation made by the patentee with respect to claim construction.11 Could this have any bearing on cancelling/condensing claims to avoid excess claim fees?
It does not seem reasonable to conclude that a patentee has surrendered or disclaimed the scope of subject-matter of a patent merely by cancelling dependent claims for the purpose of avoiding excess claim fees. As discussed above, independent claims are given a construction consistent with dependent claims (i.e. encompassing their subject-matter), and the independent claims have not been cancelled or amended. Moreover, the specification will still describe the optional features of the dependent claims as part of the subject-matter of the invention. Surely, the greater consequence of such amendments is the loss of the narrower, more focused protection provided by the cancelled dependent claims. In any event, if this issue could plausibly be a concern at all, it would likely then be better to cancel entire dependent claims at the outset, rather than to incorporate their features as exemplary or optional elements in independent claims, only to later remove those features in response to an objection for alleged lack of clarity during prosecution. Further, to mitigate risk of file wrapper estoppel when claims are deleted to reduce excess claims fees, it may be prudent to add an explanation that the claims were deleted for this reason and no other.
9. Conclusion
In many cases, incorporating exemplary or optional elements into patent claims when reducing claim sets with a view to avoiding claim fees appears to provide few benefits. Unless such features are construed as being non-limiting, it seems they may be unclear and indefinite. And if they are non-limiting, they likely serve no purpose not already achieved by the description of those illustrative or optional embodiments in the specification. Adding exemplary or optional features to claim sets takes time and effort, makes the claims more complex, and may result in added expense and delay if they result in objections by the examiner during prosecution. The use of exemplary or optional features is not a substitute for a careful early assessment of which claim elements are of sufficient importance to warrant inclusion in a separate claim, even at the cost of excess claim fees.
The preceding is intended as a timely update on Canadian intellectual property and technology law. The content is informational only and does not constitute legal or professional advice. To obtain such advice, please communicate with our offices directly.
References
- Claim fees are payable only in Canadian patent applications in which examination is requested on or after October 3, 2022, i.e. the date the claim fee rules came into force.
- MOPOP section 16.03.02 (Ambiguity in Claims). Subsection 27(4) of the Patent Act provides that: “The specification must end with a claim or claims defining distinctly and in explicit terms the subject-matter of the invention for which an exclusive privilege or property is claimed” and is the usual basis for an objection to exemplary or optional claim language. Section 60 of the Patent Rules provides that “The claims must be clear and concise and must be fully supported by the description independently of any document referred to in the description,” and is rarely cited as the basis for an objection to such claim language.
- “The subject-matter of an invention is defined by the claims, in accordance with s. 27(4). The claims set out the scope of the monopoly granted under the patent and allow others ‘to ascertain with some measure of exactness the boundaries of the exclusive privilege upon which they may not trespass during the exercise of the grant’….” AstraZeneca Canada Inc. v. Apotex Inc. 2017 SCC 36 at [40]. “Patent claims are frequently analogized to ‘fences’ and ‘boundaries’, giving the ‘fields’ of the monopoly a comfortable pretence of bright line demarcation.” Free World Trust v. Électro Santé Inc. 2000 SCC 66 at [14].
- Guidelines for Examination in the European Patent Office, April 2025 Edition, Part F, Chapter IV, Section 4.9 - Optional features.
- Manual of Patent Examining Procedure (MPEP), Ninth Edition, Revision 01.2024, §2173.05(d) - Exemplary Claim Language.
- MPEP §2173.05(h) Alternative Limitations, II. “OPTIONALLY”. In Ex parte Cordova, the Board of Patent Appeals and Interferences (BPAI) held that a claim directed to “[a] fiber coated with a composition which is the reaction product of at least one aliphatic glycol containing 2 to 12 carbons with a combination of aromatic di- or trifunctional carboxylic acids and, optionally, an unsaturated aliphatic carboxylic acid . . .” would be understood to encompass a reaction mixture which contains an unsaturated aliphatic carboxylic acid and a reaction mixture which does not contain an unsaturated aliphatic carboxylic acid. In Ex parte Wu, the BPAI held that the scope of a claim directed to “[a] method for decreasing corrosion rate on a metal surface by contacting the metal surface with a composition consisting of an epoxy resin, a petroleum sulfonate and a hydrocarbon diluent optionally containing a polyamine” was clear, and the composition set forth in the claim can consist of the first three components recited or it can include a polyamine as a fourth component.
- Pharmascience Inc. v. Janssen Inc., 2023 FCA 11 at para 15, citing Whirlpool Corp. v. Camco Inc., 2000 SCC 67 at paras. 43, and 49(b), andFree World Trust v. Électro Santé Inc., 2000 SCC 66 at para. 19.
- CAD $1158.84 for 2025.
- Section 58 of the Patent Act: “When, in any action or proceeding respecting a patent that contains two or more claims, one or more of those claims is or are held to be valid but another or others is or are held to be invalid or void, effect shall be given to the patent as if it contained only the valid claim or claims.” “An overly broad claim may be declared invalid; however, under the operation of s. 58 of the Patent Act, remaining valid claims can be given effect.” AstraZeneca Canada Inc. v. Apotex Inc., 2017 SCC 36 at [46]
- Halford v. Seed Hawk Inc., 2004 FC 88 at [91], reversed in part on other grounds 2006 FCA 275, cited many times for this proposition. See also subsection 63(1) of the Patent Rules: “…a claim that includes all the features of one or more other claims (referred to in this section as a ‘dependent claim’) must refer by number to the other claim or claims and must state the additional features claimed.” (emphasis added)
- Subsection 53.1(1) of the Patent Act came into force on December 13, 2018, and provides:
(1) In any action or proceeding respecting a patent, a written communication, or any part of such a communication, may be admitted into evidence to rebut any representation made by the patentee in the action or proceeding as to the construction of a claim in the patent if
(a) it is prepared in respect of
(i) the prosecution of the application for the patent,
(ii) a disclaimer made in respect of the patent, or
(iii) a request for re-examination, or a re-examination proceeding, in respect of the patent; and
(b) it is between
(i) the applicant for the patent or the patentee; and
(ii) the Commissioner, an officer or employee of the Patent Office or a member of a re-examination board.