MOPOP - Chapter 9

The Description – November 2017

Table of Contents

9.01 Scope of this chapter – December 2010

The description, together with the claims, form the specification of an application.1 Although the claims play a prominent role in the patent system, in that they define the scope of the exclusive privilege conferred by a patent, a proper description is fundamental to a valid patent. As was noted by the Supreme Court, "[d]isclosure is the quid pro quo for valuable proprietary rights to exclusivity which are entirely the statutory creature of the Patent Act".2

The present chapter discusses the various requirements for proper disclosure under section 27(3) of the Patent Act as well as the various requirements as to the form and content of a description under the Patent Rules.

9.02 General requirements of disclosure – December 2010

The description must provide a clear and complete disclosure of the invention such that the person skilled in the art:

  1. can unambiguously identify what has been invented; and
  2. is enabled to practice this invention.3

In Consolboard Inc. v. Macmillan Bloedel (Saskatchewan) Ltd., Dickson J. noted that "the inventor must, in return for the grant of a patent, give to the public an adequate description of the invention with sufficiently complete and accurate details as will enable a workman, skilled in the art to which the invention relates, to construct or use that invention when the period of the monopoly has expired".4 The description must be able to answer the questions "What is your invention?: How does it work?"5 such that "when the period of the monopoly has expired the public will be able, having only the specification, to make the same successful use of the invention as the inventor could at the time of his application".6

It is beyond doubt that the "public" referred to in the foregoing quote takes the form of the person skilled in the art.

9.02.01 Proper disclosure

The statutory requirements of proper disclosure are set out in subsection 27(3) of the Patent Act, which requires that:

The specification of an invention must

  1. correctly and fully describe the invention and its operation or use as contemplated by the inventor;
  2. set out clearly the various steps in a process, or the method of constructing, making, compounding or using a machine, manufacture or composition of matter, in such full, clear, concise and exact terms as to enable any person skilled in the art or science to which it pertains, or with which it is most closely connected, to make, construct, compound or use it;
  3. in the case of a machine, explain the principle of the machine and the best mode in which the inventor has contemplated the application of that principle; and
  4. in the case of a process, explain the necessary sequence, if any, of the various steps, so as to distinguish the invention from other inventions.

Thorson P. summarized the foregoing requirements in Minerals Separation North American Corp. v. Noranda Mines, Ltd.,7 noting that

[t]he description must be correct; this means that it must be both clear and accurate. It must be free from avoidable obscurity or ambiguity and must be as simple and distinct as the difficulty of description permits. It must not contain erroneous or misleading statements calculated to deceive or mislead the persons to whom the specification is addressed and render it difficult for them without trial and experiment to comprehend in what manner the invention is to be performed. It must not, for example, direct the use of alternative methods of putting it into effect if only one is practicable, even if persons skilled in the art would be likely to choose the practicable method. The description of the invention must also be full; this means that its ambit must be defined, for nothing that has not been described may be validly claimed. The description must also give all information that is necessary for successful operation or use of the invention, without leaving such result to the chance of successful experiment, and if warnings are required in order to avert failure such warnings must be given. Moreover, the inventor must act uberrima fides and give all information known to him that will enable the invention to be carried out to its best effect as contemplated by him.8

The foregoing touches on both aspects of a sufficient disclosure: that it set out in clear and precise terms what the invention is (i.e. a correct and full description), and that it provide sufficient instructions to the person skilled in the art so that this person is enabled to reproduce and successfully operate the claimed invention.

9.02.02 Addressee is the person skilled in the art

The specification of an invention is directed to a person skilled in the art or science to which it pertains, or with which it is most closely connected.9 Whether or not a description is sufficient depends on the interpretation it would be given by the person skilled in the art, who must interpret it with a mind willing to understand10 and desirous of success.11

The person skilled in the art is competent, and represents an average, logical but unimaginative worker in the field.12 This person is neither a dull-witted incompetent nor a creative, intuitive expert,13 albeit that in a highly technical field the person skilled in the art may be presumed to have expert-level knowledge and skills.14 Furthermore, the person skilled in the art is reasonably diligent in keeping up with advances in the field or fields of relevance to the invention,15 and has the advantage of being multilingual and thereby being able to comprehend prior art in any language.16

In addition, the person skilled in the art need not be an actual individual; they are a fictitious construct and can represent a team of individuals whose conjoint knowledge is relevant to the invention in suit.17

In order to properly assess whether a correct and full description of the invention has been provided, it is necessary to identify the person skilled in the art to which the application is directed.

In accordance with paragraph 80(1)(b) and 80(1)(d) of the Patent Rules, the description must indicate the technical field of the invention and must allow an understanding of the technical problem being addressed and the solution to that problem through the invention.18 The person skilled in the art will be competent in the field or fields of relevance to the invention.

A complexity arising from the nature of the person skilled in the art is that, as a general rule, neither the inventors nor the examiner may be directly equated to this person. Examiners and inventors, for example, are not free of creativity and intuition. They may have knowledge that surpasses that expected of the person skilled in the art in a given field, but again may not be as skilled in other fields of the invention as this person. During examination, an examiner must attempt to interpret the application and the prior art using the appropriate knowledge that the person skilled in the art would have possessed at the relevant date see 9.02.03. This may be particularly challenging where knowledge in the field at the date of examination has significantly developed since the relevant date, and particularly where certain views held at the relevant date have subsequently been found to be incorrect.19

Where the precise nature of the person skilled in the art is relevant for resolving an issue during examination, the examiner will determine who this person is and will take due account of any representations made by the applicant on point.

9.02.03 Description supplemented by common knowledge

A description sufficient to allow the person skilled in the art to practice the invention with the same success as the inventor is said to be enabling. Since the person skilled in the art is the addressee of the description, it is not necessary for common knowledge to be comprehensively disclosed nor to teach to the person skilled in the art things that would be plainly obvious to them.20

The date at which the person skilled in the art brings their knowledge to bear on the application is the date on which the application came into their possession; that is to say, the publication date.21

Since the common general knowledge may develop between the filing date and the publication date, this theoretically means that a specification that was not enabling as filed could nevertheless, on the basis of more extensive common general knowledge, be enabling by the publication date. However, the invention must still be fully described as of the filing date, and the utility of the invention must have been established no later than at this date see 12.04.02.

9.02.04 Misleading or erroneous statements

The person skilled in the art will read a description with a mind willing to understand and desirous of success. They will use their common general knowledge to supplement the description in order to successfully operate the invention, and will overlook obvious errors or omissions that can be readily corrected.22

Where, however, a description includes statements that direct the person skilled in the art to attempt to practice the invention in a manner contrary to their common general knowledge, the person skilled in the art will nevertheless follow these explicit instructions. Where the manner of operation so disclosed will in fact not work to achieve the promise of the invention, the description does not comply with subsection 27(3) of the Patent Act.23

[For guidance regarding misleading definitions in the description, see 9.05.03.]

9.02.05 Addressee not to be presented with problems to solve

The person skilled in the art can be called upon to perform routine experiments to ensure proper operation of an invention, but must be able to practice the full scope of the invention without undue burden or the need to exercise their inventive ingenuity.

If the person skilled in the art is called on to solve problems in such a manner that undue burden or an inventive step are required, the description is insufficient (and the attendant claims are unsupported).24 The obligation of the patentee for proper disclosure in this sense was described in Rice v. Christiani & Nielsen as:

[h]e must so draft his specification, that a person having a competent knowledge of the industry concerned […] will be able readily to ascertain from it the relation the invention bears to the existing knowledge in the industry, and so that one should not be called upon to do experimental work in order to discover how the invention may be made operative. There must be an open exposition by the patentee of everything that is necessary for the easy and certain procurement of the commodity for which the patent was granted. The patentee is not to tell a man to make an experiment but to tell him how to do the thing.25

H.G. Fox later described the relationship between the specification and the person skilled in the art as follows:

[t]he person to whom the specification is addressed is presumed to possess all the existing knowledge common to the art to which the invention relates; this knowledge he must bring to bear in interpreting the specification. But he is not required to exercise or to be possessed of more, and, if the specification contains something that necessitates the working out of a problem, the patent cannot be supported.

Where a specification describes an invention sufficiently clearly to enable a reasonably skilled workman to make use of it, even though some experiments are necessary, the patent will be good so long as those experiments do not require any exercise of the inventive faculty.26

In certain arts, it is common to describe an invention as relying on materials having certain required properties (a metal with a certain ductility; an insulator with a certain dielectric value, a molecule with a certain dipole moment), rather than by naming the materials explicitly. This is permissible as long as identifying those materials that have the required property does not require undue burden or inventive effort.

Requiring the absence of inventive effort implies that the solution to the problem being addressed must be readily apparent to the person skilled in the art (i.e. obvious). Solving a problem with a readily apparent solution is routine, and a description that requires the solving of such a problem could nevertheless be considered to be sufficient. The Courts have noted that it can be considered uninventive to engage in "routine testing to determine characteristics of known compounds, not undertaken for the purpose of 'searching for something novel', but rather for the purpose of verifying the actual attributes of already known compounds".27

While verifying the predicted or predictable properties of known compounds may therefore be considered to be routine,28 "verification" means "confirmation" and determining the unexpected and unpredictable properties of new compounds is consequently not "verification".29

This reasoning can be extended to disciplines other than the chemical arts by formulating the statement as: a certain amount of routine testing is permitted in order to identify suitable materials for operating an invention, presuming the person skilled in the art knows or has been taught the necessary properties, how to determine them, and broadly what existing materials are likely to possess them.

Examples 1

An invention describes a particular type of flange for connecting a plumbing fixture to a pipe, wherein it is necessary to construct the flange using a metal whose ductility is within a certain range. Identifying this operative ductility range is the discovery underlying the invention. Several metals having the necessary ductility are identified, and general teachings are given as to what types of metals are likely to have the necessary property. Testing ductility is within the common general knowledge of the person skilled in the art, and is routine.


1. A flexible flange for connecting a plumbing fixture to a pipe, said flange comprising a metal having ductility in the range x-y and […]


The claim is given breadth by defining the flange in terms of a metal having ductility in the defined range, rather than in terms of specific operative metals. Whether or not the claim as defined is enabled depends on whether it can be operated without placing undue burden on the person skilled in the art. This depends on whether the person skilled in the art can readily identify suitable metals. Given that the person skilled in the art can test a given metal to determine whether or not it has the necessary ductility, that for many metals this data is already available in published references, and that the description suggests which metals are likely to be suitable, there is no invention in identifying metals that have the necessary property. Verifying the properties of known metals is "routine", and the person skilled in the art has not improperly been presented with problems to solve.

Examples 2

An applicant asserts as their invention drug compositions having very uniform release profiles for the active ingredient. Certain embodiments are disclosed based on particular salts of protected cyclic amines, but the invention is claimed in terms of drug compositions having the beneficial release profile, and not in terms of drug compositions of the particular family of salts.


1. A medicament having a release profile characterized by [description of the profile]


Consider that the release profile achieved is an unexpected and very beneficial property of the specific salts disclosed. The description does not disclose what chemical properties of the salt led to the defined release profile, nor does it guide the person skilled in the art as to what other compounds may provide a similar result. In order to operate the full scope of the claim, the person skilled in the art would have to solve the problem of identifying all the other salts that would lead to the same release profile. Since the identity of these other salts (presuming some may exist) is unobvious, an inventive step is associated with their identification. The description is insufficient to support the invention as broadly asserted.

9.02.06 Theory of the invention

As a general proposition, it is not necessary for the description to provide a theory as to why the invention operates as it does. The requirement is, simply, that the description teaches the person skilled in the art what the invention is and how to make it operate to provide the promised benefits.

Thus, as noted in Apotex v. Wellcome, "[i]t is generally not necessary for an inventor to provide a theory of why the invention works. Practical readers merely want to know that it does work and how to work it".30

This general proposition, however, has to be understood in an appropriate context. The Supreme Court thus added to the comment quoted above by stating, in respect of an invention relying on sound prediction, that "[i]n this sort of case, however, the sound prediction is to some extent the quid pro quo the applicant offers in exchange for the patent monopoly".31 It can consequently be understood that if the utility of the invention is predicated on a sound prediction [see 12.08.04], and the line of reasoning depends on an understanding of the theory as to why the invention works, it may not be possible to properly express the line of reasoning unless this theory is disclosed.

9.03 Disclosing a solution to a practical problem – November 2017

As was noted by the Supreme Court in Apotex v. Wellcome, the granting of patents is "a method by which inventive solutions to practical problems are coaxed into the public domain".32 Being a solution to a practical problem is what provides to the invention the practical utility necessary for patentability.

The description must put the person skilled in the art in a position to appreciate the nature of the problem being solved and the solution provided by the invention. For applications filed on or after October 1, 1996, paragraph 80(1)(d) of the Patent Rules explicitly provides that the description shall

describe the invention in terms that allow the understanding of the technical problem, even if not expressly stated as such, and its solution.

In order to solve a practical problem, the solution must be in a form that can interact directly with the physical world and, hence, that will itself enable a person skilled in the art to obtain the intended result or benefit. That is, a patent is given for "the means by which a result is obtained … rather than the result itself".33 These means must consist of one or several elements, where an element in this sense could be either a physical object (a machine, article of manufacture or composition of matter) or a step leading to a physical effect in an art or process.

The group of elements that are made use of to obtain the benefit of the invention may, in combination, be referred to as the "practical form" of the invention (i.e. the form in which the invention may be practised). The practical form includes all the elements required to provide the utility of the invention.

In order for the description to properly disclose the practical form, it must supplement the common general knowledge of the person skilled in the art so as to put the invention into the hands of this person. Any novel element must therefore be fully described, as it was necessarily not previously known. Also, those elements (new or old) the person skilled in the art would not have known to use in combination to achieve the objects of the invention must be described, not only individually but in the appropriate combination.

For the description to disclose a patentable invention, it must describe (and the claims define) all the elements necessary to provide the useful result in a novel and inventive manner, and without which elements the solution would cease to be inventive.34

It is also necessary that the description provide such instructions as are necessary for the person skilled in the art to understand, where applicable, the interrelationship of the elements necessary to provide the practical form of the invention. The invention must be described so that, colloquially speaking, "the wheels will go round",35 and must not require that the person skilled in the art perform modifications to the invention described in order to make it work.36

Although external documents may be referred to in the description, the invention must be described and enabled by the description alone as interpreted by the person skilled in the art in view of their common general knowledge. Specific prior art knowledge (e.g. information only available in one or a few documents, and which has not been shown to be commonly known and accepted) may be considered not to be "common general knowledge", and in such cases those specific teachings from the prior art necessary to describe or enable the invention must be included in the description in order to provide a full and complete disclosure.

It is not necessary to supplement a description of the foregoing with a description of those elements that would be self-evidently necessary to operate the invention, and whose use in the context of the invention as described would be obvious to the person skilled in the art.37

During prosecution, amendment to the claims may appear to alter the nature of the invention. Care must be taken to ensure that the inventor was, no later than the filing date, in possession of the invention asserted in the amended claims. Inventive ingenuity cannot post-date filing.40 This is particularly relevant where features not identified in the original specification as being related to specific advantages are subsequently asserted as rendering the claims non-obvious over prior art disclosures. It is important to consider whether the description teaches that the elements in question are simply optional, or are essential elements of preferred embodiments. Where the inclusion of an element will lead to additional benefits over the invention as broadly disclosed, it should be viewed as an essential element of the "narrower invention" (the subject-matter in a claim of narrower scope).

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9.04.03 Combinations

A combination, in the sense the term is used herein, is an assemblage of parts (often of known parts) whose conjoint use leads to a result that is "different from the sum of the results of the elements" that make it up and "that is not attributable to any of the elements but flows from the combination itself and would not be possible without it".55 Such a result may conveniently be termed a "unitary" result.56

A patentable combination has been explained in the following way:

it is accepted as sound law that a mere placing side by side of old integers so that each performs its own proper function independently of any of the others is not a patentable combination, but that where the old integers when placed together have some working inter-relation producing a new or improved result then there is patentable subject matter in the idea of the working inter-relation brought about by the collocation of the integers.57

Where several parts are used together, each providing its expected result and the whole not leading to a unitary result, the assemblage is referred to as a "mere aggregation",58 or simply as an "aggregation", to distinguish it from a true combination.

The utility of a combination is the unitary result it provides, and it is this result that must be established by demonstration or sound prediction.

Where, having described the structure of the combination, it would not be clear to the person skilled in the art what unitary result it achieves, a correct and full description of the result itself may be necessary to show that the combination is useful and inventive and to distinguish it from a mere aggregation.

9.05 Special topics – December 2010

The following sections set out practice in respect of certain specific topics which give rise to particular considerations with respect to proper disclosure.

9.05.01 Functional limitations

In certain cases, applicants may wish to describe or define an invention using functional language. The use of functional language, whether in a claim or in the description, is not per se objectionable. Such language, however, is generally used to provide breadth and must be carefully considered from the perspective of proper support.

Functional limitations must always be considered from the perspective of the person skilled in the art, with the question to be asked being: "can the person skilled in the art practice, in view of the description, the full breadth of the claimed invention without recourse to undue experimentation or inventive ingenuity?" see 9.02.05. If the means to effect the defined function are common general knowledge, the functional limitation is unlikely to be objectionable. Where few or only one means is known to effect the function, however, broad functional language would direct the claimed invention to be practised in ways that have not been fully described or enabled and consequently would be objectionable.

Typically, the inquiry into the appropriateness of functional language is driven by the language of the claims. Where an invention is defined in terms of an overly broad functional limitation, the claim seeks to monopolize speculative embodiments that the inventors have not adequately described. The corollary is that the description is not sufficient to support the invention as claimed.

To paraphrase Free World Trust v. Électro Santé Inc., it is not legitimate to invent a particular composition that grows hair on bald men and thereafter claim all compositions that grow hair on bald men.59

Thus, a claim to "a composition comprising a hair-growth activating compound in a pharmaceutically acceptable carrier", where only compound X is known to provide the function, would be too broad. The limitation "hair-growth activating" is a functional limitation to the scope of the compounds found in the composition, but does not serve to make the scope of the claim clear to the person skilled in the art. Identifying all the compounds that would have this activity would require extensive inventive experimentation amounting to invention see 9.02.05. The description, therefore, is not sufficient to describe and enable the invention asserted in the claim, and is objectionable under subsection 27(3) of the Patent Act.

In contrast, if it had been discovered that the combination of a particular drug with any non-steroidal anti-inflammatory (NSAID) compound led to unexpected advantages, functionally limiting the scope of the second component of the composition by the limitation "NSAID" would not be problematic. The scope of the term "NSAID" (or "NSAID compound") would be immediately apparent to the person skilled in the art.

Similarly, in a mechanical invention that relies on a "cutting means", a number of different cutting means would be known to the person skilled in the art. Where it would be readily apparent which would be suitable for operating the claimed invention, the limitation "cutting means" would not improperly broaden the claim. The identification and selection of appropriate cutting means would not require undue effort or further invention in such a circumstance.

9.05.02 Disclosure of biotechnological inventions

Specific disclosure requirements exist for some inventions in the fields of biotechnology. In brief, it may be necessary for a sequence listing of a nucleotide or amino acid sequence to be included with the description or for a deposit of biological material to be made with an International Depository Authority in order for the description of a biotechnology invention to be considered to be sufficient.

Details on the requirements for providing sequence listings or deposits of biological material are provided in subsection 17.05.07 and section 17.06, respectively, of this manual.

9.05.03 The applicant as their own lexicographer

It has long been understood that the language of the claims is to be construed in view of the specification as a whole, and that the applicant can serve as their own lexicographer.

Their Lordships do not doubt that it is possible for a patentee to make his own dictionary in this way. If he has put something in the earlier part of the specification which plainly tells the reader that for the purpose of the specification he is using a particular word with a meaning which he sets out, then the reader knows that when he comes to the claims he must read that word as having that meaning. But this is an awkward method of drafting and is very undesirable where a simpler method could easily be adopted and it is in all cases incumbent on a patentee who chooses to adopt this method to make his intention plain to those who read the specification.60

During examination, the language of the claims is interpreted by giving each term its plain and usual meaning in the art to which the invention pertains, unless it is clear from the description that a term in the claims is to be given a different meaning.

In the context of proper disclosure, it is to be noted that where an applicant, in attempting to act as their own lexicographer, creates a definition for a term that is contrary to the usual meaning ascribed to that term in the art, that is liable to cause confusion or ambiguity, or that is unnecessary in that other plain language could as easily provide the same information, the definition is objectionable. Recall in this context the requirement discussed in 9.02.01 that "[t]he description must be correct; this means that it must be both clear and accurate. It must be free from avoidable obscurity or ambiguity and must be as simple and distinct as the difficulty of description permits".

For example, where the description teaches that, for the purposes of the invention, the symbol P (phosphorus) designates nitrogen (elemental symbol N), this definition is only liable to cause confusion and is objectionable under subsection 27(3) of the Patent Act. The symbol is recognized in chemistry as designating phosphorus, and could readily be replaced by the appropriate symbol, N, to designate nitrogen.

In contrast, a definition is generally acceptable if, for the purposes of expediency and without sacrificing clarity, it narrows the scope of a term that would otherwise be attributed a broader meaning in the art. In a given case, it might be acceptable to define, for example, that the term "ethylene polymer" means "a non-crosslinked polymer comprising at least 80 mol% ethylene, with up to 20% C3-8 alkene comonomer". Providing the longer definition at multiple instances would be unnecessarily cumbersome, and the definition provided unambiguously restricts the broader term.

9.05.04 Disclosure of trademarked products

An invention may be operated by way of trademarked products. Simply naming a trademarked product is not, however, equivalent to describing the composition of that product.

Further, simply knowing what components are included in a trademarked product does not identify which of those components is an essential element of the invention (i.e. which component or components are necessary to fulfill the trademarked product's role in the invention). Thus, even though a person skilled in the art may, depending on the state of the art, be able to reverse engineer a trademarked product and identify its components, this will not by necessity put them in possession of the invention.

Therefore, where an invention is described only in terms of a trademarked product, the question of proper support must be carefully considered. If it is not clear which component of the product is responsible for the product's role in the invention, the invention cannot be operated other than by the trademarked product itself.

If the composition of the trademarked product is not known, and the product is not commercially available, the invention is not enabled.

Where an invention is described in terms of specific components (e.g. chemical compounds), but is supported by examples that rely on trademarked products of undisclosed composition, no presumption exists that the examples embody the invention described. The applicant must establish that they were aware of the composition of the trademarked product no later than at the filing date.

Where the composition of a trademarked product did not form part of the prior art as of the filing date, its composition cannot subsequently be added to the application see 9.08.

[For requirements regarding the identification of trademarks, see 9.07.03.]

9.05.05 Description by reference to the claims

The invention must be "correctly and fully" described in the description, which according to section 2 of the Patent Rules is "that part of the specification other than the claims". Furthermore, in accordance with section 84 of the Patent Rules, the claims shall be fully supported by the description.

It is consequently improper for the description to state the nature of the invention by reference to the claims. Such statements suggest that the description does not "correctly and fully" disclose the invention and does not comply with subsection 27(3) of the Patent Act.

Therefore, where the description teaches in some fashion that the invention is "according to the claims", the statement must be removed or replaced by an explicit description of the invention.

By way of example, statements such as "the problem of premature ignition in the combustion chamber is overcome through the method of claim 1" or "the compositions as instantly claimed exhibit superior insecticidal properties" fail to set forth explicitly what the invention in question is, but suggest instead that the invention is whatever might be claimed at any given moment in time.

Note that amending the description to include the language of the claims originally filed is necessarily compliant with subsection 38.2(2) of the Patent Act.

9.05.06 Statements expanding the scope of the claims

This subsection has been deleted.

9.05.07 References to foreign practice or law

Where an application includes a statement whose correctness is dependent on foreign patent prosecution practices or laws, such a statement may be inaccurate or liable to cause confusion in the context of Canadian law. Where this is the case, the statement must be removed. The statements may be viewed as being "incorrect", and therefore a defect under subsection 27(3) of the Patent Act see 9.09.

An indication that the application is a continuation-in-part or a divisional of a foreign patent document, for example, is not correct in the context of the Canadian Patent Act and must be removed.

A statement regarding the rights of foreign governments to the invention may also be misleading, and should be removed if it is inaccurate.

9.06 Form of the description – December 2010

The form a description should take is set out in section 80 of the Patent Rules.62 Thus,

  1. The description shall
    1. state the title of the invention, which shall be short and precise and shall not include any trademark, coined word or personal name;
    2. specify the technical field to which the invention relates;
    3. describe the background art that, as far as is known to the applicant, can be regarded as important for the understanding, searching and examination of the invention;
    4. describe the invention in terms that allow the understanding of the technical problem, even if not expressly stated as such, and its solution;
    5. briefly describe the figures in the drawings, if any;
    6. set forth at least one mode contemplated by the inventor for carrying out the invention in terms of examples, where appropriate, and with reference to the drawings, if any; and
    7. contain a sequence listing where required by subsection 111(1).
  2. The description shall be presented in the manner and order specified in subsection (1) unless, because of the nature of the invention, a different manner or a different order would afford a better understanding or a more economical presentation.

The provisions of subsection 80(2) of the Patent Rules would allow, for example, that drawings associated with the prior art be described with the background art, prior to the brief description of the figures in any remaining drawings.

The title of the invention should be descriptive of the invention in suit, and not merely of the field to which the invention pertains. A title such as "flame-retardant rigid polyurethane foam" is acceptable, whereas "foam" is not.63

In accordance with paragraph 80(1)(a) of the Patent Rules, the Office considers the title provided in the description to be the correct title of the invention. Where, for any reason, the title ascribed to the invention in the Office's electronic database differs from the title provided in the description, the electronic database will be updated at the time of grant to reflect the title set out in the description.64

Disagreement between the title in the description and the title in the Office's electronic database is not a defect in the application. An examiner may note the existence of such a disagreement, in order to apprise the applicant of the situation and provide them with an opportunity to address the matter. Such a disagreement may also be brought to the applicant's attention subsequent to allowance, by way of an Office letter.

Paragraph 80(1)(c) of the Patent Rules requires that the applicant describe the background art that, as far as is known to them, is important for the understanding, searching and examination of the invention. Where relevant background art is identified during prosecution, an applicant may, within the limitations imposed by section 38.2 of the Patent Act see 9.08, introduce to the description references to and descriptions of the contents of prior art documents where these are clearly admitted to be prior art with respect to the application. Examiners should, in general, not raise an objection simply because the description has not been amended to identify background art brought to the applicant's attention subsequent to filing.

Paragraph 80(1)(f) of the Patent Rules provides that, "where appropriate", the applicant must set forth in terms of examples, at least one mode contemplated by the inventor for carrying out the invention. The use of the wording "where appropriate" in this rule reflects that an exemplary basis may or may not be necessary depending on the case at hand. The language "where appropriate" does not merely mean "if the applicant deems it appropriate", and does not provide any exception to the disclosure requirements of subsection 27(3) of the Patent Act.

It is not necessary for the description to present the information required by section 80 of the Patent Rules in sections bearing headings corresponding to the paragraphs of subsection 80(1), although an applicant may choose to do so for the sake of clarity.

Headings such as "Summary of the Invention", "Detailed Description of the Invention" and "Detailed Description of the Preferred Embodiments" are permitted in Canadian practice. It is worth noting, however, that where a heading such as "Detailed Description of the Preferred Embodiments" is used, support for claims broader than these embodiments must be found in other parts of the description which must satisfy the requirements of subsection 27(3) of the Patent Act, including enablement and support for any sound prediction, in respect of the invention as broadly claimed.

9.07 Formalities requirements of the description – December 2010

The description is subject to many formalities requirements dealing with various aspects of its contents and presentation. These are summarized in the following sections.

9.07.01 Pages of the description

In accordance with subsection 73(1) of the Patent Rules the description must be on consecutively numbered pages,65 and in accordance with section 72 of the Patent Rules no page of the description may contain anything belonging to another part of the application.66

9.07.02 Drawings, graphics and tables

In accordance with section 74 of the Patent Rules, the description shall not contain drawings67 but may contain chemical or mathematical formulae or the like.68 For greater clarity, a chemical formula may be presented in the description in graphical form (i.e. as a structure).69 The description may also contain information presented in tables. In accordance with subsection 75(2) of the Patent Rules, any formula or table may, where it aids presentation, be presented sideways (i.e. in landscape format) with the top of the formula or table at the left side of the sheet.70 Otherwise, subsection 75(1) of the Patent Rules provides that pages of the description must be used upright (i.e. in portrait format).71

It can be inferred from section 37 of the Patent Act that a drawing is an illustration of the invention. Schematics that illustrate a process, such as flow-charts, are generally considered to be drawings.

Graphical representations of data, such as graphs, histograms, pie charts, and spectra, are not necessarily to be viewed as "illustrations of the invention", and therefore may be included in the description. Where a graphical representation of data is provided as a drawing, it must comply with all the requirements of section 82 of the Patent Rules.

Tabulated data generally cannot be considered a "drawing", and typically should be presented in the description.

Where the application contains drawings, subsection 82(9) of the Patent Rules requires that any reference characters appearing on any figures in the drawings, and only these reference characters, be mentioned in the description.72 Further, where features are identified by reference characters, subsection 82(10) of the Patent Rules requires that the same reference characters must be used throughout the description to refer to those features, and may not be used to refer to any other features.73

9.07.03 Identification of trademarks

In accordance with section 76 of the Patent Rules, any trademark mentioned in the application shall be identified as such.74 The Office requires that each trademark be identified in an appropriate manner at least once, preferably at its first appearance.

Use of the words "trademark" in parentheses, of the designation "TM", or of an indicator such as an asterisk (*) linked to a footnote denoting that the asterisk designates a trademark are all examples of appropriate manners for identifying a trademark in an application.

9.07.04 Identification of documents

In accordance with section 81 of the Patent Rules, a document referred to in the description must be available to the public and be fully identified, and shall not be incorporated by reference.75

The Office considers a patent document to be properly identified when the country or office code is provided along with a number under which the published version of the document can be found. Thus, the number provided can be that given to a granted patent, or be either the application number or publication number of a published application.

WO 96/937212, US 5,410,288, and EP 1 004 793 are examples of patent documents properly identified by a publication or patent number.

PCT CA2006/001,285 and U.S.S.N. 11/421,399 are examples of application numbers which are acceptable if the identified application has been published.

PCT applications, and US applications filed after November 28, 2000, will generally be published unless the application has been withdrawn (or, in the case of US applications, abandoned) prior to the publication date.  Under 35 U.S.C. 122, a US application may also be kept confidential (i.e. will not be published) if the applicant certifies that they will not file an application for the disclosed invention in any other country.  Where a US application is relied on as a priority document, this provision does not apply. US provisional applications, applications for design patents, and applications in series 09 or earlier are not necessarily published and may not be referred to by their application numbers unless the document is available to the public.76

For non-patent documents, the requirement is that the document be sufficiently well identified to permit it to be obtained by an interested party.

For a journal article, textbook, or the like, the document should be identified by the names of the author and the publication, the year of publication, the volume and/or issue number(s) if applicable, and the page numbers of the article, number of the chapter or the like. Preferably, the title of an article or title of a chapter should be provided. Additional information, such as the name of the publisher, may be included. Where a unique document identifier such as an ISBN code is provided, this does not replace any of the foregoing requirements.

References to internet pages present a particular difficulty in that neither the URL nor the content of such pages is necessarily fixed. Examiners will object to the identification of a document by way of a URL where it is not clear that the URL refers to a reliable, publically available source that can reasonably be expected to ensure the information in question is of fixed content and will be more or less permanently retrievable.

9.08 Amendments to the description – December 2010

In accordance with subsection 38.2(1) of the Patent Act, the description is subject to amendment before grant. Under subsection 38.2(2) of the Patent Act, any such amendment may not introduce "matter not reasonably to be inferred from the specification or drawings as originally filed, except in so far as it is admitted in the specification that the matter is prior art with respect to the application" (for convenience, such matter may be referred to simply as "new matter").

Note that one amendment that is always permissible from the standpoint of "new matter" is the inclusion of the language of the originally filed claims in the description.

General guidance regarding the amendment of applications is provided in chapter 19 of the manual.

As regards the description, particular attention must be given to amendments that replace restrictive language with permissive language. Where an application teaches that the invention (as opposed to an embodiment of the invention) "must be" or "is" (or the like) operated in a certain way, amendment of this language to indicate that the invention "preferably" or "optionally" (or the like) is operated in that way enlarges the scope of the invention and may be seen as the addition of new matter.

Similarly, it is possible for the deletion of text to amount to the addition of new matter. If a passage in the description teaches that an invention is inoperative under certain conditions, an amendment to remove this guidance could be viewed as introducing new matter by expanding the scope of the operable invention.

Where a description included both permissive and restrictive language regarding a certain limitation, amending the description to make it self-consistent throughout will generally not be seen as the addition of new matter.

An invention requires an inventive step, and the presence of this inventive step must be evaluated in view of the specification as filed. Amendments that appear to introduce new aspects of "inventiveness" to the application introduce new matter.

Remembering that an invention is a solution to a practical problem, it can be understood that amendments that tend to transform the invention as originally disclosed into a new invention - that is to say, into a new solution to the same or a different problem - constitute the addition of new matter.

Such amendments shift the point of invention and have the effect of causing a different invention to be disclosed than that in the specification as originally filed.

The description may be amended to make reference to prior art documents. Where the amendment is merely to clarify the state of the art, this will generally not be considered to introduce new matter. Where, however, an amendment introduces information from a prior art document, these amendments may, depending on the circumstances, introduce new matter.

Where specific teachings in a prior art document are required in order to enable the invention to be operated, or in order to support a sound prediction of utility, and it would not have been clear to the person skilled in the art, as of the claim date, which teachings in the prior art document were necessary for this purpose, identifying or including the specific teachings constitutes the addition of new matter.

9.09 Office actions on the description – December 2010

Objections dealing with substantive issues of sufficiency are presented under subsection 27(3) of the Patent Act, or a specific paragraph of that subsection where this precision may be helpful in underlining the basis of the objection.

As is the case with objections under subsection 27(4) of the Patent Act, however, the defects being objected to under subsection 27(3) can range from significant issues of sufficiency to fairly minor defects of clarity. The presence of a subsection 27(3) objection is not by necessity an indication of any un-remediable defect relating to sufficiency.

Nevertheless, wherever a more specific authority exists on which to base the objection being made, this authority should be used in place of subsection 27(3) of the Patent Act. For example, if a reference character has been included in the drawings but is not mentioned in the description, this defect should be presented under subsection 82(9) of the Patent Rules rather than under subsection 27(3) of the Patent Act.

Objections to formatting or other minor problems are presented under authority of whichever section relates to the defect under consideration see 9.07 and the related endnotes].

Non-compliance with the formatting requirements set out in sections 68, 69 and 70 of the Patent Rules [see section 5.03 of this manual] can be identified by an examiner in order to inform applicants of any defects and expedite advancing the application to allowance. It is not, however, required for an examiner to do so, since correction of these defects can also be requisitioned by examination support staff. It is noted that the Canadian requirements as to formatting are based on those required under the Patent Cooperation Treaty, and requisitioning compliance with the Canadian requirements is therefore permissible under Article 27, PCT.

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