CASRIP Newsletter - Spring/Summer 1998, Volume 5, Issue 2
Clarity of Patent Claims
It is generally recognized that patent claims serve two important functions: they measure the invention for determining patentability, and they determine the extent of protection conferred by a patent.
For both aspects, a construction of the claim language is necessary. As far as patentability is concerned, it has to be determined if the invention as defined in the claim is properly delimited from the prior art and whether what is claimed can be carried out. In order to facilitate the determination of whether the invention as claimed is patentable, it is necessary that the meaning of the claims be clear.
The second aspect mentioned relates to the scope of the patent. The principle of legal certainty requires that the public should not be left in any doubt as to which subject matter is covered by a particular patent and which is not. Since the claims determine the extent of protection, the claims have to be clear for the sake of legal certainty.
Although the principles as outlined above are adopted in various patent law systems and are reflected in article 6 of the Patent Corporation Treaty (PCT), there are important differences among different systems, and there seem to be no general standards with respect to when a patent claim is clear and when is not. This may pose significant problems for an applicant who wishes to obtain patent protection for an invention in different countries and has to draft suitable claims.
In the following, the general requirement of clear claims under the European Patent Convention (EPC) is discussed. Moreover, specific aspects of the clear-claim requirement are compared to the corresponding provisions of U.S. patent law in order to highlight the practice of the European Patent Office.
2. "Clear Claims" under Article 84 of the EPC
Article 84 of the European Patent Convention lays down the principles governing the content and wording of claims: "The claims shall define the matter for which protection is sought. They shall be clear and concise and be supported by the description."
Thus, article 84 of the EPC contains a provision that explicitly requires clarity of the claims. In a decision of a Technical Board of Appeal, it was held that this requirement was fulfilled if a claim used clear language that did not give rise to misinterpretation of its wording. This also implies that the claims per se must be free of contradictions.
In order to facilitate the further construction of this provision, and especially of the term "clear," one may resort to rule 29 that supplements article 84. According to first sentence of rule 29 (1), "[t]he claims shall define the matter for which protection is sought in terms of the technical features of the invention."
Article 84 and rule 29 both refer to the matter for which protection is sought so that the requirement of clarity means that the definition of the matter for which protection is sought has to be clear. It may therefore be concluded that a claim lacks clarity if the exact distinctions which delimit the scope of protection cannot be learnt from it. This is also in line with the already mentioned principle of legal certainty.
However, the above concept of the term "clear" is still very general and has to be put in more concrete terms, especially with respect to the "technical features" which have to be used to define the invention. It is, in other words, necessary to further lay down how technical features have to be stated in a claim so that the claim is clear in the sense of article 84. This is a question which does not only relate to the claim but also to the description so that one may resort to rule 35, which relates to the whole application documents. According to rule 35 (12), the last sentence, "[i]n general, use should be made of the technical terms, signs and symbols generally accepted in the field in question."
From this provision, the additional requirement that the technical features of the invention have to be described by usual technical terms may be deduced. This serves the same purpose as article 84. The Guidelines  conclude that the words in a claim should be given the meaning and scope which they normally have in the relevant art. However, they also suggest that a claim should be read with an attempt to make technical sense out of it, which may involve a departure from the strict literal meaning of the wording. Moreover, it has also been considered that the words used in a claim may be given a special meaning in the description.
In such a case, the question arises as to which function the description has for constructing the claim language. The EPC contains a provision for the construction of claims only in the context of the extent of protection conferred by a European patent or a European patent application. According to article 69 (1) of the EPC, "[t]he extent of protection conferred by a European patent or a European patent application shall be determined by the terms of the claims. Nevertheless, the description and drawings shall be used to interpret the claims."
The Protocol on the Interpretation of Article 69 of the Convention further specifies that the claims do not serve only as a guideline in the determination of the extent of protection. On the other hand, the Protocol states that the extent of protection is not "to be understood as that defined by the strict literal meaning of the wording used in the claims, the description and the drawings being employed only for resolving an ambiguity found in the claims."
Thus, there is no doubt that the description and the drawings have to be considered for the construction of the claim language in the case of infringement. For this reason, it is also necessary to avoid any inconsistency between the claims and the description, since this may create uncertainty with respect to the extent of protection and therefore render the claim unclear. However, a controversy has arisen with respect to the role of the description in the context of the clarity of the claims. In other words, the controversy is about the question whether the description has to be considered for the interpretation of possibly unclear technical terms in a claim.
In T 2/80  the Board held that it must be possible to understand the claims without reference to the description. This holding has been further elaborated in T 454/89  in which the Board stated that the claims must be clear in themselves when read with normal skills, including knowledge of the prior art, but not any knowledge derived from the description. The Board argued that article 69 was not concerned about a claim's definition of the matter for which protection is sought, as was article 84, so that the provision that the description and the drawings shall be used to interpret the claims did not apply in the context of the clarity of the claims. Obviously, this interpretation is the basis for the suggestion in the Guidelines that the examiner, if words in a claim are given a special meaning in the description, "should, so far as possible, require the claim to be amended; whereby the meaning is clear from the wording of the claim alone." 
However, in T 860/93  the Board held that the claims had to be interpreted in their context. In the Board's view, this followed from the general principle of law that a proper interpretation of a document was to be derived by having regard for the document as a whole. This in turn means that the description and the drawings have to be considered in interpreting the claim language, as stipulated by article 69 (1) of the EPC. The Board therefore concluded that this provision applied also to the clarity requirement of article 84 of the EPC.
The Board further pointed out that the determination of the extent of protection was only one case where the interpretation of the words of a claim was required, since such an interpretation had to be done by every examining or opposition division before it could decide on novelty and inventive step. The different Boards have indeed repeatedly stated that when the content of a claim has to be assessed objectively to determine whether the subject matter is patentable, the description and drawings should be used to interpret the claim.
It may thus be concluded that the description and the drawings should always be considered if the claim language has to be interpreted, also in connection with article 84 of the EPC. However, amendments, based on the disclosure in the whole application documents, may be necessary if the claim language is not clear, even if the meaning of the words in the claims can be understood in view of the description.
3. Definiteness of the Claim Language in U.S. Patent Law
U.S. patent law does not explicitly mention the requirement of clarity. However, 35 U.S.C. §112 contains the following provision: "The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention." This has been interpreted as essentially a requirement for precision and definiteness of the claim language which must make clear what subject matter the claims encompass.
The requirement of definiteness is fulfilled if someone skilled in the art understands the bounds of the claims, with the necessary degree of precision depending on the nature of the subject matter. The underlying principle is, as under the EPC, that the public is entitled to know the scope of the claims. However, according to U.S. law, the public cannot rely on the claim language by itself but must look to both the patent specification and the prosecution history, especially where there is doubt concerning the scope of the claims.
Unlike the European clarity requirement, the U.S. requirement of definiteness does not mean that the patentee would be obliged to use usual technical terms or technical terms in their usual meaning. In the first step of constructing the claim language of a U.S. patent, the words are given their ordinary and customary meaning. However, the patentee may be his or her own lexicographer. He or she may choose to use terms in a manner other than their ordinary meaning. This has to be considered if the special definitions of the terms are clearly stated in the patent specification or the file history.  Thus, even if the patentee assigns to words a broader than the conventional meaning, this does not make the claims invalid for indefiniteness if the specification makes clear which the intended meaning is.
On the other hand, in the context of infringement, a word in a claim may not be understood in such a broad sense that someone skilled in the art cannot reasonably determine which embodiments are within the scope of the claims and which are not, even if the description provides a basis for such a broad construction. In such a case, the requirement of definiteness would not be fulfilled.
4. Clarity and Enabling Disclosure
Clarity of the claim language is only one requirement that a European patent application has to fulfill. Another is, of course, that the application must contain an enabling disclosure. At least at the first glance, there seems to be an overlap between the requirement of clarity as defined in article 84 of the EPC and the requirement of article 83 of the EPC that "[t]he European patent application must disclose the invention in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art." However, whereas article 84 refers specifically to the claims, article 83 relates to the whole application. Thus, the question arises as to how detailed the invention must be defined in the claims.
In T 1055/92 the Board reached the conclusion that it is not always necessary that a claim identify technical features or steps in detail since the primary function of a claim is to set out the extent of protection for the invention. In order to meet the requirement of article 83 of the EPC, it is only necessary that the claims, together with the description and drawings, describe the invention in such a degree of detail that someone skilled in the art can perform it, using his common general knowledge, within the whole area that is claimed. Enabling disclosure is, however, a requirement not relevant in the context of clarity of the claims.
On the other hand, the legal principle that the patent monopoly should be justified by the technical contribution to the art is reflected not only by the requirement of enabling disclosure of the invention in the application documents as a whole, but also by the requirement that the claims must be supported by the description (art. 84).
This additional requirement with respect to the claims means that all essential features of the invention, i.e., those features described in the description as necessary to carry out the invention, must be present in the independent claim. The independent claim must, in other words, contain all those technical features necessary to solve the technical problem underlying the invention. It should not extend to subject matter which, on the basis of the description, is not at the disposal of the person skilled in the art.
Similar to this requirement of support of the claims by the description according to the EPC, U.S. patent law requires that the claims conform to the invention as set forth in the remainder of the specification. Therefore, the claims must be clear (or definite) and must be supported by the description. That the specification as a whole must sufficiently disclose the invention is a different requirement.
5. Procedural Aspects
Lack of clarity of the claims of a European patent application may be objected to during the examination based on article 84 in conjunction with article 96(2) of the EPC. If the objection is not overcome, for instance, by amending the claims, the patent application may be refused (art. 97 (1) EPC). It is, however, important to note that lack of clarity is neither a ground for opposition (art. 100 EPC) nor a ground for revocation of a European patent (art. 138 EPC) in a national invalidation under the law of a Contracting State.
Thus, if a patent has been granted by the EPO, it cannot be contested merely because the claims are unclear. In addition, if an opposition has been filed on other grounds, lack of clarity of the claims as granted cannot be a basis for the revocation of the patent. However, if the proprietor files amended claims during the opposition proceedings, the opposition division will, when examining if the patent as amended fulfills the requirements of the EPC, also take article 84 into account.
Already in G9/91 the Enlarged Board of Appeal held that amendments to the claims and to other parts of a patent during the opposition or appeal procedure shall be examined in full with respect to the requirements of the EPC. In T 694/92, this led the Board to the conclusion that article 84 may constitute a ground for revoking a patent if objections to either clarity or support arise out of amendments to the patent as granted. In addition, a lack of clarity of the claims may play an indirect role in deciding such patentability issues as novelty, inventive step or sufficiency of disclosure in opposition proceedings, even if lack of clarity does not arise out of an amendment.
In T 923/92 the Board held that a certain vague expression in the claim ("has human tissue plasminogen activator function") left the skilled reader in doubt as to the exact meaning of the term. The Board attributed to this feature the broadest possible meaning and reached the conclusion that the disclosure was not sufficient to carry out the invention over the whole range claimed, including "a vast catalogue of derivatives of human t-PA of unspecified structure having any unspecified function of human t-PA."  Thus, despite the limitation of the grounds for opposition (or invalidation in national proceedings), the requirement of clarity is relevant also after the grant of a European patent.
Complications similar to those arising out of the peculiar role of article 84, which is relevant for a patent application but not directly applicable after a grant, do not arise under U.S. patent law, because the requirement of claim definiteness applies not only during examination before the USPTO, but also if the validity of a patent is questioned. Thus, procedural aspects will not be discussed in more detail with respect to the U.S. patent system.
6. Special Cases
6.1 Broad Technical Terms
The Technical Boards of Appeal have repeatedly held that broad claims are not unclear merely because of their breadth. The breadth of a claim cannot be contested on its own, but only in conjunction with other criteria, such as novelty, inventive step or reproducibility. It does not follow from article 84 of the EPC that a claim is objectionable simply because it is "unreasonably broad."
In T 238/88  the board held that a broad term could not be objected to as unclear if the meaning of that term was unambiguous for a person skilled in the art, either per se or in light of the description. The term in question, the chemical designation "alkyl" for certain moieties in organic molecules, was regarded as clear as it stood since it was a well-known technical term of art which was commonly used in the chemical field and did not imply any ambiguity.
With respect to another broad term used for the definition of the claimed compounds, the Board held that terms which were not usual terms in the art should be interpreted in light of the description. The Board applied this holding to the term "substituted groups," which was not found objectionable since potential substituents were listed in the description. In such a case, however, it would usually be required to incorporate the definition given in the description into the claim.
In another decision in the field of chemistry, the Board found that, under the circumstances of the case, the term "substituted" had the ordinary technical meaning, namely, "substituted by absolutely anything." The Board regarded the term as broad, but clear in the sense of article 84.
Similar considerations seem to apply under U.S. patent law. "The legal standard for definiteness is whether a claim reasonably apprises those of skill in the art of its scope." Whether what is claimed is new, useful, nonobvious, or otherwise patentable is a different issue.
6.2 Relative Terms
According to the Guidelines, relative terms should be used in a claim only if the term has a well-recognized meaning in the particular art, e.g., "high-frequency" in relation to an amplifier, and this is the meaning intended. Terms such as "thin", "wide" or "strong" should preferably not be used.
In T 860/93  the Board regarded the term "water-soluble" used to characterize the claimed cellulose ether derivatives as clear to the skilled reader in the given context. The specification did not contain any information with respect to how that property should be determined. However, the applicant had provided evidence in the form of copies from a dictionary stating that "most cellulose ethers are water-soluble polymers." The Board concluded that the authors of that text would have expected the skilled reader to understand what degree of solubility was meant by "water-soluble" in that context so that, in the absence of evidence backing the applicant's assertions, the claim directed to water-soluble cellulose ether derivatives was found to be not objectionable under article 84 of the EPC.
Obviously, a much stricter standard was applied in T 337/95. Here the Board regarded the term "lower alkyl" as unclear. The Board started from the finding that the requirement of clarity in article 84 of the EPC meant that the public should not be left in any doubt as to which subject matter was covered by a particular patent and which was not. Thus, if a claim is directed to a group of chemical compounds, the definition of the compounds must be such that a skilled person can distinguish unambiguously those chemical compounds belonging to the claimed group from those not belonging to it.
In this case, one of the substituents of the claimed compounds was designated as "lower alkyl." The Board objected this term because an upper limit on the number of carbon atoms contained in a lower alkyl group could not be fixed precisely. In order to overcome the objection, the applicant filed copies from textbooks. However, he could only demonstrate that the term "lower alkyl" was used in the relevant technical field, but not that it had a generally accepted meaning. Especially, no unambiguous value for the upper limit with respect to the number of carbon atoms could be derived from the cited literature.
The Board then examined whether an upper limit on the number of carbon atoms could be derived from the description. However, the description did not contain a definition of "lower alkyl," but merely some examples of such groups. Such non-limiting exemplification was not regarded as conclusive evidence for a definite upper limit on the number of carbon atoms in a lower alkyl group. Thus, the Board concluded that the compounds claimed could not be clearly distinguished from those not claimed and that such a term as "lower alkyl" could not be allowed in a claim directed to a group of organic compounds per se. It should be noted that the objection under article 84 of the EPC was not based on the breadth of the term used to define the compounds. In fact, the Board would probably not have objected to the much broader term "alkyl" as unclear.
The USPTO, in contrast to the EPO, did not find the term "lower alkyl" objectionable. A U.S. patent with the term "lower alkyl" in the claim to define a group of compounds similar to those claimed in the aforementioned European case was granted. However, the standard applied in the U.S. is not principally different from the European standard. In another case in the field of chemistry, claims were held invalid for indefiniteness because someone skilled in the art could not determine whether a given compound was within the scope of the claims. The claims were, in other words, not sufficiently precise to permit a potential competitor to determine whether or not he or she is infringing.
With respect to relative terms in general, the Court of Appeal for the Federal Circuit ruled that technical terms were not per se indefinite when expressed in qualitative terms (such as "relatively small") without numerical limits. The court held that a "patentee has the right to claim the invention in terms that would be understood by persons of skill in the field of the invention." It may, however, be necessary that the specification provide a standard for measuring the degree if words of degree (such as "substantially equal to") are used in a claim.
6.3 "About" and Similar Terms
In the practice of the European Patent Office, the word "about" or similar terms, such as "approximately," as applied to an individual value or a range, can be permitted only if it does not prevent the invention from being unambiguously distinguished from the prior art.
Similarly, the Court of Appeals for the Federal Circuit held that the word "about" might make a claim indefinite and thus invalid when the meaning of the claim was in doubt, especially when there is close prior art. The court noted that nothing in the specification, prosecution history, or prior art provided any indication as to what range should be covered by the term "about."
Therefore, terms like "about" should be used only with care. In addition, it may be necessary to define such a term in the specification if a property can be measured only with some uncertainty.
6.4 Definition of Products by Parameters or Process Features
In T 94/82  the Board ruled that the requirement of clarity could be fulfilled in a claim to a product if the characteristics of the product were specified by parameters related to the physical structure of the product, provided that those parameters could be clearly and reliably determined by objective procedures which were usual in the art.
If a claim contains parameters to define the subject matter, it may, in order to define the parameters unambiguously, be necessary to include details with respect to the method of measuring the parameters into the claim . The inclusion of such details may, however, be avoided if a person of skill in the art would know which method to employ or if all available methods yield the same result.
According to the Guidelines, the characterization of a chemical product solely by its parameters is generally not allowed. If, however, the invention cannot be adequately defined in any other way, the applicant may resort to such a definition by parameters. It is then required that, as mentioned above, the parameters can be clearly and reliably determined.
Similarly, product-by-process claims are allowable only if, under the circumstances of the particular case, the claimed product cannot be defined in any other way. It is thus assumed that there is a "hierarchy" of the means to define the subject matter. In other words, the assumption is that the identification of a product in the field of chemistry or biochemistry by structural features is, in general, more likely to allow a clear definition of the subject matter for which protection is sought than the more indirect identification by parameters or features relating to the production of the product.
Under U.S. patent law, the definition of a product by physical parameters which characterize that product is permissible. It is also permissible to define a product by a process by which it is made. However, at least according to an older decision, product-by-process claims may be used only if a product cannot be defined in structural terms. This is in line with the requirement of definiteness insofar as it is more difficult to determine what products are covered by a product-by-process claim than by a claim with structural limitations.
6.5 Functional Features
As has already been mentioned, in the practice of the European Patent Office, claims are not held unclear merely because they are broad. An example of broad claims is those containing functional language; such claims are often referred to as "means plus function" claims.
In the jurisdiction of the Boards of Appeal, it is generally recognized that it is not necessary that every feature in a claim be expressed in terms of a structural limitation  because the applicant would otherwise in many cases not be able to obtain an adequate protection for the invention. In several decisions, the Boards have worked out criteria to decide when a functional definition of a feature instead of a structural limitation is permissible. These are summarized in T 694/92. Accordingly, the essential technical features may be expressed in general functional terms,
- if, from an objective point of view, such features cannot otherwise be defined more precisely without restricting the scope of the claim, and
- if these features provide instructions which are sufficiently clear for the skilled person to reduce them to practice without undue burden, i.e., with no more than a reasonable amount of experimentation, and without applying inventive skill.
Therefore, the interests of the applicant or patentee, respectively, on the one hand and the interests of the public on the other hand must be balanced. Claims containing functional language will often be objected to not because they lack clarity, but because they are not supported by the description (which is also a requirement of article 84 of the EPC) or encompass, because of their broad functional language, embodiments not sufficiently disclosed (art. 83 EPC).
As far as the field of chemistry is concerned, the Board ruled in T 435/91 that the disclosure was not sufficient if only isolated examples were disclosed but a component in a composition was defined by its function, provided that "a technical concept fit for generalization which would enable the skilled person to achieve the envisaged result within the whole ambit of the claim containing the functional definition" was not disclosed at the same time.
With respect to the requirement that the claims must be supported by the description, the Guidelines  state that an objection arises if the application conveys the impression that a function has to be carried out in a particular way, but the claim also embraces other means of performing the function.
In the U.S., the use of functional language in a claim is explicitly admitted in 35 U.S.C. §112, Paragraph 6. The statute also lays down how the scope of such claims is determined. This provision of a rather narrow interpretation of means-plus-function claims under U.S. patent law has no parallel in the European Patent Convention. However, with respect to disclosure and support of elements defined in a claim by their function, the U.S. and European patent systems seem to agree to a great extent.
In the U.S. practice, it is required that the specification contains an adequate disclosure showing what is meant by the functional language used in the claims. "If an applicant fails to set forth an adequate disclosure, the applicant has in effect failed to particularly point out and distinctly claim the invention as required by the second paragraph of section 112."
"The very nature of words would make a clear and unambiguous claim a rare occurrence." Despite this statement of a U.S. court, clarity or definiteness is a major requirement for patent claims. In this context, the clarity requirement according to the EPC seems to be stricter than the requirement of definiteness of the claim language under the U.S. system. In the U.S., patentee may choose to be his or her own lexicographer, whereas the EPC requires that usual technical terms be used to define the subject matter for which protection is sought. Moreover, under the EPC, it is necessary to include precise definitions in the claims because an objection to lack of clarity can often not be overcome by referring to the description. In contrast, under U.S. patent law, claims must be definite when read in light of the description. Thus, the applicant for a European patent should carefully choose the technical terms used to define the claimed subject matter in order to obtain a broad protection.
Another aspect which deserves special attention is that the possibilities of amending a claim objected to as unclear are restricted by the provision that, after filing of the patent application, no new matter may be introduced. Thus, as a measure of precaution, it seems advisable to include, at least in the description, definitions of the technical terms relevant to the definition of the invention. It is not sufficient to merely provide examples, since replacing an objected term by specific examples may lead to a significant reduction in scope.
"The specification and claims of a patent . . . constitute one of the most difficult legal instruments to draw with accuracy" this seems to be especially true if protection for an invention is sought in countries with different legal systems.
Dr. Markus Breuer
 Cf. e.g., G 2/88 - Friction reducing additive/MOBIL OIL III, OJ EPO 1990, 93; Corr. OJ EPO 1990, 469, Nos. 2.4 and 2.5 of the reasons for the decision; Donald S. Chisum and Michael A. Jacobs, Understanding Intellectual Property Law. New Y ork: Matthew Bender & Co., 1992, § 2D[d]. See also Toshiko Takenaka, Interpreting Patent Claims: The United States, Germany and Japan. 17 IIC Studies (1995).
 T 337/95 - Lower alkyl/NIHON NOHYAKU, OJ EPO 1996, 628.
 T 1055/92 - Clarity/Ampex Corporation, OJ EPO 1995, 214 (No. 3 of the reasons for the decision).
 T 2/80, OJ EPO 1981, 431.
 T 165/84 (not published in OJ EPO).
 Guidelines for the Examination in the European Patent Office, published by the European Patent Office, 1994 (revised in July 1995).
 Guidelines, Part C, Chapter III, 4.2.
 This is a question the national courts have to deal with. For Germany, see for instance, BGH GRUR 89, 903 - "Batteriekastenschnur."
 Guidelines, Part C, Chapter III, 4.3.
 T 454/89 (not published in OJ EPO).
 T 860/93 - Protective coating compositions/AQUALON, OJ EPO1995, 47.
 Cf. e.g., T 23/86, OJ EPO 1987, 316; T 16/87, OJ EPO 1992, 212.
 In re Borkowski, 422 F.2d 904, 909, 164 U.S.P.Q. 642, 646 (CCPA 1970); In re Hammack, 427 F.2d 1378, 1382, 166 U.S.P.Q. 204, 208 (CCPA 1970). Cf. PPG Industries, Inc. v. Guardian Industries Corp., 75 F.3d 1558, 37 U .S.P.Q.2d 1618 (Fed. Cir. 1996).
 Miles Laboratories, Inc. v. Shandon Inc., 997 F.2d 870, 27 U.S.P.Q.2d 1123 (Fed. Cir. 1993).
 Texas Instruments Inc. v. U.S. Int'l Trade Comm'n, 871 F.2d 1054, 10 U.S.P.Q.2d 1257 (Fed. Cir. 1989).
 Vitronics Corporation v. Conceptronic, Inc., 90 F.3d 1576 (Fed. Cir. 1996).
 Beachcombers, International, Inc. v. WildeWood Creative Products, Inc., 31 F.3d 1154, 31 U.S.P.Q.2d 1653 (Fed. Cir. 1994).
 Genentech, Inc. v. The Wellcome Foundation, Ltd., 29 F.3d 1555, 31 U.S.P.Q.2d 1161 (Fed. Cir. 1994).
 T 1055/92 - Clarity/Ampex Corporation, OJ EPO 1995, 214.
 T 409/91 - Fuel oils/EXXON, OJ EPO 1994, 653.
 Code of Federal Regulations, Title 37, §1.75, paragraph (d)(1).
 W.L. Gore & Associates, Inc. v. Garlock, Inc., 721 F.2d 1540, 220 U.S.P.Q. 303 (Fed. Cir. 1983); Miles Laboratories, Inc. v. Shandon Inc., 997 F.2d 870, 27 U.S.P.Q.2d 1123 (Fed. Cir. 1993).
 G 9/91 - Power to examine/ROHM AND HAAS, OJ EPO 1993, 408 (No. 19 of the reasons for the decision).
 T 694/92 - Modifying plant cells/MYCOGEN, OJ EPO 1997, 408.
 T 923/92 - Human t-PA/GENENTECH, OJ EPO 1996, 564.
 In the U.S., the problem arose as to how the term "human tissue plasminogen activator" had to be understood in the context of an alleged infringement. The court held that a broad, functional definition was not acceptable, and it instead assigned a narrow, structural definition to that term. Cf. Genentech, Inc. v. The Wellcome Foundation, Ltd., 29 F.3d 1555, 31 U.S.P.Q.2d 1161 (Fed. Cir. 1994).
 Cf. e.g., Kingsdom Medical Consultants, Ltd. v. Hollister Inc., 863 F.2d 867, 9 U.S.P.Q.2d 1384 (Fed. Cir. 1988).
 T 523/91 (not published in OJ EPO).
 T 939/92 - Triazoles/AGREVO, OJ EPO 1996, 309.
 T 238/88 - Crown ether/KODAK, OJ EPO 1992, 709.
 In re Warmerdam, 33 F.3d 1354, 31 U.S.P.Q.2d 1754 (Fed. Cir. 1994).
 Guidelines, Part C, Chapter III, 4.5.
 Cf. the decisions discussed above. Of course, the broader term might have been objectionable on other grounds, for instance, lack of enabling disclosure.
 US Patent 5,112,384.
 Morton International, Inc. v. Cardinal Chemical Co., 5 F.2d 1464, 28 U.S.P.Q.2d 1190 (Fed. Cir. 1993).
 Modine Manufacturing Co. v. U.S. Int'l Trade Comm'n, 75 F.3d 1545, 37 U.S.P.Q.2d 1609 (Fed. Cir. 1996).
 Seattle Box Co., Inc. v. Industrial Crafting & Packing, Inc., 731 F.2d 818, 221 U.S.P.Q. 568 (Fed. Cir. 1984); 756 F.2d 1574, 225 U.S.P.Q. 357 (Fed. Cir. 1985).
 Guidelines, Part C, Chapter III, 4.5a.
 Amgen, Inc. v. Chugai Pharmaceutical Co., 927 F.2d 1200, 18 U.S.P.Q.2d 1016 (Fed. Cir. 1991).
 T 94/82, OJ EPO1984, 75.
 Guidelines, Part C, Chapter III, 4.10.
 Guidelines, Part C, Chapter III, 4.7a.
 Cf. e.g., T 552/91, Chroman derivatives/MERCK, OJ EPO 1995, 100; T 130/90 (not published in OJ EPO).
 Cf. e.g., W.L. Gore & Associates, Inc. v. Garlock, Inc., 721 F.2d 1540, 220 U.S.P.Q. 303 (Fed. Cir. 1983).
 In re Brown, 29 F.2d 873 (D.C. Cir. 1928).
 Guidelines, Part C, Chapter III, 2.1.
 Cf. e.g., T 301/87, "Alpha- Interferone/BIOGEN, OJ EPO 1990, 335.
 Cf., e.g., T68/85, OJ EPO 1987, 228.
 T435/91 - Detergents/UNILEVER, OJ EPO 1995, 188.
 Guidelines, Part C, Chapter 6.5.
 In re Donaldson Co., 16 F.3d 1189, 29 U.S.P.Q.2d 1845 (Fed. Cir. 1994).
 Autogiro Co. of America v. United States, 384 F.2d 391, 155 U.S.P.Q. 697 (Ct. Cl. 1967).
 Cf. e.g., T 552/91 - Chroman derivatives/MERCK, OJ EPO 1995, 100.
 Slimfold Manufacturing Co., Inc. v. Kinkead Industries, Inc., 810 F.2d 1113, 1 U.S.P.Q.2d 1563 (Fed. Cir. 1987).