Source: https://bitlaw.com/source/mpep/1850.html
Timestamp: 2019-04-24 20:05:30+00:00

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The international application shall relate to one invention only or to a group of inventions so linked as to form a single general inventive concept ("requirement of unity of invention").
Where a group of inventions is claimed in one and the same international application, the requirement of unity of invention referred to in Rule 13.1 shall be fulfilled only when there is a technical relationship among those inventions involving one or more of the same or corresponding special technical features. The expression "special technical features" shall mean those technical features that define a contribution which each of the claimed inventions, considered as a whole, makes over the prior art.
The determination whether a group of inventions is so linked as to form a single general inventive concept shall be made without regard to whether the inventions are claimed in separate claims or as alternatives within a single claim.
Subject to Rule 13.1, it shall be permitted to include in the same international application a reasonable number of dependent claims, claiming specific forms of the invention claimed in an independent claim, even where the features of any dependent claim could be considered as constituting in themselves an invention.
Any designated State in which the grant of a utility model is sought on the basis of an international application may, instead of Rules 13.1 to 13.4, apply in respect of the matters regulated in those Rules the provisions of its national law concerning utility models once the processing of the international application has started in that State, provided that the applicant shall be allowed at least two months from the expiration of the time limit applicable under Article 22 to adapt his application to the requirements of the said provisions of the national law.
37 C.F.R. 1.475 Unity of invention before the International Searching Authority, the International Preliminary Examining Authority and during the national stage.
(a) An international and a national stage application shall relate to one invention only or to a group of inventions so linked as to form a single general inventive concept ("requirement of unity of invention"). Where a group of inventions is claimed in an application, the requirement of unity of invention shall be fulfilled only when there is a technical relationship among those inventions involving one or more of the same or corresponding special technical features. The expression "special technical features" shall mean those technical features that define a contribution which each of the claimed inventions, considered as a whole, makes over the prior art.
(c) If an application contains claims to more or less than one of the combinations of categories of invention set forth in paragraph (b) of this section, unity of invention might not be present.
(d) If multiple products, processes of manufacture or uses are claimed, the first invention of the category first mentioned in the claims of the application and the first recited invention of each of the other categories related thereto will be considered as the main invention in the claims, see PCT Article 17(3)(a) and § 1.476(c).
(e) The determination whether a group of inventions is so linked as to form a single general inventive concept shall be made without regard to whether the inventions are claimed in separate claims or as alternatives within a single claim.
I. THE REQUIREMENT FOR "UNITY OF INVENTION"
Any international application must relate to one invention only or to a group of inventions so linked as to form a single general inventive concept (PCT Article 3(4)(iii) and 17(3)(a), PCT Rule 13.1, and 37 CFR 1.475 ). Observance of this requirement is checked by the International Searching Authority and may be relevant in the national (or regional) phase.
The decision in Caterpillar Tractor Co. v. Commissioner of Patents and Trademarks, 650 F. Supp. 218, 231 USPQ 590 (E.D. Va. 1986) held that the Patent and Trademark Office interpretation of 37 CFR 1.141(b)(2) as applied to unity of invention determinations in international applications was not in accordance with the Patent Cooperation Treaty and its implementing regulations. In the Caterpillar international application, the USPTO acting as an International Searching Authority, had held lack of unity of invention between a set of claims directed to a process for forming a sprocket and a set of claims drawn to an apparatus (die) for forging a sprocket. The court stated that it was an unreasonable interpretation to say that the expression "specifically designed" as found in former PCT Rule 13.2(ii) means that the process and apparatus have unity of invention if they can only be used with each other, as was set forth in MPEP § 806.05(e).
Therefore, when the Office considers international applications as an International Searching Authority, as an International Preliminary Examining Authority, and during the national stage as a Designated or Elected Office under 35 U.S.C. 371, PCT Rule 13.1 and 13.2 will be followed when considering unity of invention of claims of different categories without regard to the practice in national applications filed under 35 U.S.C. 111. No change was made in restriction practice in United States national applications filed under 35 U.S.C. 111 outside the PCT.
In applying PCT Rule 13.2 to international applications as an International Searching Authority, an International Preliminary Examining Authority and to national stage applications under 35 U.S.C. 371, examiners should consider for unity of invention all the claims to different categories of invention in the application and permit retention in the same application for searching and/or preliminary examination, claims to the categories which meet the requirements of PCT Rule 13.2.
PCT Rule 13.2, as it was modified effective July 1, 1992, no longer specifies the combinations of categories of invention which are considered to have unity of invention. Those categories, which now appear as a part of Chapter 10 of the International Search and Preliminary Examination Guidelines, may be obtained from the Patent Examiner’s Toolkit link or from WIPO’s website (www.wipo.int/pct/en/texts/gdlines.html ). The categories of invention in former PCT Rule 13.2 have been replaced with a statement describing the method for determining whether the requirement of unity of invention is satisfied. Unity of invention exists only when there is a technical relationship among the claimed inventions involving one or more special technical features. The term "special technical features" is defined as meaning those technical features that define a contribution which each of the inventions considered as a whole, makes over the prior art. The determination is made based on the contents of the claims as interpreted in light of the description and drawings. Chapter 10 of the International Search and Preliminary Examination Guidelines also contains examples concerning unity of invention.
II. DETERMINATION OF "UNITY OF INVENTION"
An international application should relate to only one invention or, if there is more than one invention, the inclusion of those inventions in one international application is only permitted if all inventions are so linked as to form a single general inventive concept (PCT Rule 13.1 ). With respect to a group of inventions claimed in an international application, unity of invention exists only when there is a technical relationship among the claimed inventions involving one or more of the same or corresponding special technical features. The expression "special technical features" is defined in PCT Rule 13.2 as meaning those technical features that define a contribution which each of the inventions, considered as a whole, makes over the prior art. The determination is made on the contents of the claims as interpreted in light of the description and drawings (if any).
Whether or not any particular technical feature makes a "contribution" over the prior art, and therefore constitutes a "special technical feature," should be considered with respect to novelty and inventive step. For example, a document discovered in the international search shows that there is a presumption of lack of novelty or inventive step in a main claim, so that there may be no technical relationship left over the prior art among the claimed inventions involving one or more of the same or corresponding special technical features, leaving two or more dependent claims without a single general inventive concept.
Lack of unity of invention may be directly evident "a priori," that is, before considering the claims in relation to any prior art, or may only become apparent "a posteriori," that is, after taking the prior art into consideration. For example, independent claims to A + X, A + Y, X + Y can be said to lack unity a priori as there is no subject matter common to all claims. In the case of independent claims to A + X and A + Y, unity of invention is present a priori as A is common to both claims. However, if it can be established that A is known, there is lack of unity a posteriori, since A (be it a single feature or a group of features) is not a technical feature that defines a contribution over the prior art.
Although lack of unity of invention should certainly be raised in clear cases, it should neither be raised nor maintained on the basis of a narrow, literal or academic approach. There should be a broad, practical consideration of the degree of interdependence of the alternatives presented, in relation to the state of the art as revealed by the international search or, in accordance with PCT Article 33(6), by any additional document considered to be relevant. If the common matter of the independent claims is well known and the remaining subject matter of each claim differs from that of the others without there being any unifying novel inventive concept common to all, then clearly there is lack of unity of invention. If, on the other hand, there is a single general inventive concept that appears novel and involves inventive step, then there is unity of invention and an objection of lack of unity does not arise. For determining the action to be taken by the examiner between these two extremes, rigid rules cannot be given and each case should be considered on its merits, the benefit of any doubt being given to the applicant.
From the preceding paragraphs it is clear that the decision with respect to unity of invention rests with the International Searching Authority or the International Preliminary Examining Authority. However, the International Searching Authority or the International Preliminary Examining Authority should not raise objection of lack of unity of invention merely because the inventions claimed are classified in separate classification groups or merely for the purpose of restricting the international search to certain classification groups.
Unity of invention has to be considered in the first place only in relation to the independent claims in an international application and not the dependent claims. By "dependent" claim is meant a claim which contains all the features of one or more other claims and contains a reference, preferably at the beginning, to the other claim or claims and then states the additional features claimed (PCT Rule 6.4 ). The examiner should bear in mind that a claim may also contain a reference to another claim even if it is not a dependent claim as defined in PCT Rule 6.4. One example of this is a claim referring to a claim of a different category (for example, "Apparatus for carrying out the process of Claim 1...," or "Process for the manufacture of the product of Claim 1..."). Similarly, a claim to one part referring to another cooperating part, for example, "plug for cooperation with the socket of Claim 1...") is not a dependent claim.
If the independent claims avoid the prior art and satisfy the requirement of unity of invention, no problem of lack of unity arises in respect of any claims that depend on the independent claims. In particular, it does not matter if a dependent claim itself contains a further invention. For example, suppose claim 1 claims a turbine rotor blade shaped in a specified manner such that it avoids the prior art, while claim 2 is for a "turbine rotor blade as claimed in claim 1" and produced from alloy Z. Then no objection under PCT Rule 13 arises either because alloy Z was new and its composition was not obvious and thus the alloy itself already contains the essential features of an independent possibly later patentable invention, or because, although alloy Z was not new, its application in respect of turbine rotor blades was not obvious, and thus represents an independent invention in conjunction with turbine rotor blades. As another example, suppose that the main claim defines a process avoiding the prior art for the preparation of a product A starting from a product B and the second claim reads: "Process according to claim 1 characterized by producing B by a reaction using the product C." In this case, too, no objection arises under PCT Rule 13, whether or not the process for preparation of B from C is novel and inventive, since claim 2 contains all the features of claim 1. Equally, no problem arises in the case of a genus/species situation where the genus claim avoids the prior art, provided the genus claim is directed only to alternatives of a similar nature and the species falls entirely within the genus. To determine if a genus claim is directed only to alternatives "of a similar nature," see subsection III.B. below. Moreover, no problem arises in the case of a combination/subcombination situation where the subcombination claim avoids the prior art and the combination claim includes all the features of the subcombination.
If, however, an independent claim does not avoid the prior art, then the question whether there is still an inventive link between all the claims dependent on that claim needs to be carefully considered. If there is no link remaining, an objection of lack of unity a posteriori (that is, arising only after assessment of the prior art) may be raised. Similar considerations apply in the case of a genus/species or combination/subcombination situation.
This method for determining whether unity of invention exists is intended to be applied even before the commencement of the international search. Where a search of the prior art is made, an initial determination of unity of invention, based on the assumption that the claims avoid the prior art, may be reconsidered on the basis of the results of the search of the prior art.
Alternative forms of an invention may be claimed either in a plurality of independent claims, or in a single claim. In the latter case, the presence of the independent alternatives may not be immediately apparent. In either case, however, the same criteria should be applied in deciding whether there is unity of invention. Accordingly, lack of unity of invention may exist within a single claim. Where the claim contains distinct embodiments that are not linked by a single general inventive concept, the objection as to lack of unity of invention should be raised. PCT Rule 13.3 does not prevent an Authority from objecting to alternatives being contained within a single claim on the basis of considerations such as clarity, the conciseness of claims or the claims fee system applicable in that Authority.
Objection of lack of unity of invention does not normally arise if the combination of a number of individual elements is claimed in a single claim (as opposed to distinct embodiments as discussed in the paragraph immediately above), even if these elements seem unrelated when considered individually.
(C) Intermediate and final products.
Principles for the interpretation of the method contained in PCT Rule 13.2, in the context of each of those situations are set out below. It is understood that the principles set out below are, in all instances, interpretations of and not exceptions to the requirements of PCT Rule 13.2.
Examples to assist in understanding the interpretation on the three areas of special concern referred to in the preceding paragraph are set out in Chapter 10 of the International Search and Preliminary Examination Guidelines which can be obtained from the Patent Examiner’s Toolkit link or from WIPO’s website (www.wipo.int/pct/en/texts/gdlines.html ).
(C) In addition to an independent claim for a given product, an independent claim for a process specially adapted for the manufacture of the said product and an independent claim for an apparatus or means specifically designed for carrying out the said process.
A process is specially adapted for the manufacture of a product if it inherently results in the product and an apparatus or means is specifically designed for carrying out a process if the contribution over the prior art of the apparatus or means corresponds to the contribution the process makes over the prior art.
Thus, a process shall be considered to be specially adapted for the manufacture of a product if the claimed process inherently results in the claimed product with the technical relationship being present between the claimed product and claimed process. The words "specially adapted" are not intended to imply that the product could not also be manufactured by a different process.
Also an apparatus or means shall be considered to be specifically designed for carrying out a claimed process if the contribution over the prior art of the apparatus or means corresponds to the contribution the process makes over the prior art. Consequently, it would not be sufficient that the apparatus or means is merely capable of being used in carrying out the claimed process. However, the expression "specifically designed" does not imply that the apparatus or means could not be used for carrying out another process, nor that the process could not be carried out using an alternative apparatus or means.
More extensive combinations than those set forth above should be looked at carefully to ensure that the requirements of both PCT Rule 13 (unity of invention) and PCT Article 6 (conciseness of claims) are satisfied. In particular, while a single set of independent claims according to one of (A), (B), or (C) above is always permissible, it does not require the International Authority to accept a plurality of such sets which could arise by combining the provisions of PCT Rule 13.3 (which provides that the determination of unity of invention be made without regard to whether the inventions are claimed in separate claims or as alternatives within a single claim), with the provisions set out above (thus resulting in a set based on each of a number of independent claims in the same category under PCT Rule 13.3 ). The proliferation of claims arising from a combined effect of this kind should be accepted only exceptionally. For example, independent claims are permissible for two related articles such as a transmitter and receiver; however, it does not follow that an applicant may include also, in the one international application, four additional independent claims: two for a process for the manufacture of the transmitter and the receiver, respectively, and two for use of the transmitter and receiver, respectively.
The situation involving the so-called Markush practice wherein a single claim defines alternatives (chemical or non-chemical) is also governed by PCT Rule 13.2. In this special situation, the requirement of a technical interrelationship and the same or corresponding special technical features as defined in PCT Rule 13.2, shall be considered to be met when the alternatives are of a similar nature.
(2) In cases where the common structure cannot be the unifying criteria, all alternatives belong to a recognized class of chemical compounds in the art to which the invention pertains.
In paragraph (B)(1), above, the words "significant structural element is shared by all of the alternatives" refer to cases where the compounds share a common chemical structure which occupies a large portion of their structures, or in case the compounds have in common only a small portion of their structures, the commonly shared structure constitutes a structurally distinctive portion in view of existing prior art, and the common structure is essential to the common property or activity. The structural element may be a single component or a combination of individual components linked together.
In paragraph (B)(2), above, the words "recognized class of chemical compounds" mean that there is an expectation from the knowledge in the art that members of the class will behave in the same way in the context of the claimed invention. In other words, each member could be substituted one for the other, with the expectation that the same intended result would be achieved.
The fact that the alternatives of a Markush grouping can be differently classified should not, taken alone, be considered to be justification for a finding of a lack of unity of invention.
The situation involving intermediate and final products is also governed by PCT Rule 13.2.
The term "intermediate" is intended to mean intermediate or starting products. Such products have the ability to be used to produce final products through a physical or chemical change in which the intermediate loses its identity.
(B) The intermediate and final products are technically interrelated, this meaning that the final product is manufactured directly from the intermediate or is separated from it by a small number of intermediates all containing the same essential structural element.
Unity of invention may also be considered to be present between intermediate and final products of which the structures are not known, for example, as between an intermediate having a known structure and a final product the structure of which is not known, or as between an intermediate of unknown structure and a final product of unknown structure. In order to satisfy unity in such cases, there must be sufficient evidence to lead one to conclude that the intermediate and final products are technically closely interrelated as, for example, when the intermediate contains the same essential element as the final product or incorporates an essential element into the final product.
It is possible to accept in a single international application different intermediate products used in different processes for the preparation of the final product, provided that they have the same essential structural element.
The intermediate and final products shall not be separated, in the process leading from one to the other, by an intermediate which is not new.
If the same international application claims different intermediates for different structural parts of the final product, unity shall not be regarded as being present between the intermediates.
If the intermediate and final products are families of compounds, each intermediate compound shall correspond to a compound claimed in the family of the final products. However, some of the final products may have no corresponding compound in the family of the intermediate products so that the two families need not be absolutely congruent.
If little or no additional search effort is required, reasons of economy may make it advisable for the examiner, while making the search for the main invention, to search at the same time, despite the nonpayment of additional fees, one or more additional inventions in the classification units consulted for the main invention. The international search for such additional inventions will then have to be completed in any further classification units which may be relevant, when the additional search fees have been paid. This situation may occur when the lack of unity of invention is found either " a priori " or " a posteriori."
When the examiner finds lack of unity of invention, normally, the applicant is invited to pay fees for the search of additional inventions. In exceptional circumstances, however, the examiner may be able to establish both an international search and a written opinion covering more than one invention with negligible additional work, in particular, when the inventions are conceptually very close. In those cases, the examiner may decide to complete the international search and the written opinion of the International Searching Authority for the additional invention(s) together with that for the invention first mentioned. In considering the amount of work involved, the examiner should take into account the time needed to create the written opinion as well as that needed to perform the search, since even when the additional work with regard to the search is negligible, the opposite may be the case for the written opinion of the International Searching Authority and therefore justify requesting the additional fees. If it is considered that the total additional work does not justify requesting additional fees, all results are included in the international search report (and where applicable, the written opinion) without inviting the applicant to pay an additional search fee in respect of the additional inventions searched but stating the finding of lack of unity of invention.
The search fee which the applicant is required to pay is intended to compensate the International Searching Authority for carrying out an international search and preparing a written opinion, but only where the international application meets the "requirement of unity of invention." That means that the international application must relate to only one invention or must relate to a group of inventions which are so linked as to form a single general inventive concept (PCT Articles 3(4)(iii) and 17(3)(a) ).
If the International Searching Authority finds that the international application does not comply with the requirement of unity of invention, the applicant will be informed of the lack of unity of invention by a communication preceding the issuance of the international search report and written opinion of the International Searching Authority which contains an invitation to pay additional search fees. (Form PCT/ISA/206 or USPTO/299 (telephone practice), see below). This invitation specifies the reasons the international application is not considered to comply with the requirement of unity of invention, identifies the separate inventions, and indicates the number of additional search fees and the amount to be paid (PCT Rules 40.1, 40.2(a) and (b) ). The International Searching Authority cannot consider the application withdrawn for lack of unity of invention, nor invite the applicant to amend the claims, but informs the applicant that, if the international search report is to be drawn up in respect of those inventions present other than the first mentioned, then the additional fees must be paid within one month from the date of the invitation to pay additional fees (PCT Rule 40.1 ). Such additional fees are payable directly to the International Searching Authority which is conducting the search, i.e., the USPTO, EPO, KIPO, IPAU, Rospatent, ILPO, JPO, or IPOS. The additional search fee amounts for the competent international searching authorities can be found in Annex D of the Applicant’s Guide (www.wipo.int/pct/en/appguide ).
In the invitation to pay additional fees, the International Searching Authority should set out a logically presented, technical reasoning containing the basic considerations behind the finding of lack of unity (PCT Rule 40.1 ).
Since these payments must take place within the time limit set by the International Searching Authority so as to enable the observation of the time limit for establishing the international search report set by PCT Rule 42, the International Searching Authority should endeavor to ensure that international searches be made as early as possible after the receipt of the search copy. The International Searching Authority finally draws up the international search report and written opinion of the International Searching Authority on those parts of the international application which relate to the "main invention," that is, the invention or the group of inventions so linked as to form a single general inventive concept first mentioned in the claims (PCT Article 17(3)(a) ). Moreover, the international search report and written opinion of the International Searching Authority will be established also on those parts of the international application which relate to any invention (or any group of inventions so linked as to form a single general inventive concept) in respect of which the applicant has paid any additional fee within the prescribed time limits.
Where, within the prescribed time limit, the applicant does not pay any additional fees or only pays some of the additional fees indicated, certain parts of the international application will consequently not be searched. The lack of an international search report in respect of such parts of the international application will, in itself, have no influence on the validity of the international application and processing of the international application will continue, both in the international and in the national (regional) phases. The unsearched claims, upon entry into the national stage, will be considered by the examiner and may be the subject of a holding of lack of unity of invention.
An Invitation to Pay Additional Fees and, Where Applicable, Protest Fee (Form PCT/ISA/206) is used to invite the applicant to pay additional search fees. In the space provided on form PCT/ISA/206, the examiner should indicate the number of inventions claimed in the international application covering which particular claims and explain why the international application is not considered to comply with the requirements of unity of invention. The examiner should then indicate the total amount of additional fees required for the search of all claimed inventions.
(C) multiple dependent claims which do not comply with PCT Rule 6.4(a) (see MPEP § 1843.03).
In the box provided at the top of the form, the time limit of one month for response is set according to PCT Rule 40.1. Extensions of time are not permitted.
Form PCT/ISA/206 must be signed by an examiner with at least partial signatory authority.
When the telephone practice is used in making lack of unity requirements, it is critical that the examiner orally inform applicant that there is no right to protest the holding of lack of unity of invention for any group of invention(s) for which no additional search fee has been paid.
The examiner must further orally advise applicant that any protest to the holding of lack of unity or the amount of additional fee required must be filed in writing no later than one month from the mailing date of the international search report. The examiner should fill in the information on Form USPTO/299 "Chapter I PCT Telephone Memorandum for Lack of Unity" as a record of the telephonic holding of lack of unity.
If the applicant or the legal representative or agent refuses to either agree to a search limited to the first mentioned invention or authorize payment of additional fees over the telephone, or if applicant does not have a deposit account, the examiner should send a written invitation using Form PCT/ISA/206.
If a written invitation is required, the examiner should, if possible, submit the written invitation to the Technology Center for review and mailing within 7 days from the date the international application is charged to the examiner.
As provided in 37 CFR 1.475(a), an international application shall relate to one invention only or to a group of inventions so linked as to form a single general inventive concept ("requirement of unity of invention"). Where a group of inventions is claimed in an international application, the requirement of unity of invention shall be fulfilled only when there is a technical relationship among those inventions involving one or more of the same or corresponding special technical features. The expression "special technical features" shall mean those technical features that define a contribution which each of the claimed inventions, considered as a whole, makes over the prior art.
Products, processes of manufacture, processes of use, and apparatuses are different categories of invention. When an application includes claims to more than one product, process, or apparatus, the first invention of the category first mentioned in the claims of the application and the first recited invention of each of the other categories related thereto will be considered as the "main invention" in the claims. In the case of non-compliance with unity of invention and where no additional fees are timely paid, the international search and/or international preliminary examination, as appropriate, will be based on the main invention in the claims. See PCT Article 17(3)(a), 37 CFR 1.475(d), 37 CFR 1.476(c) and 37 CFR 1.488(b)(3).
1. Begin all Lack of Unity actions for PCT applications during the international phase (including species) with this heading.
2. Follow with form paragraphs 18.06 - 18.06.02, 18.07 - 18.07.03, as appropriate.
3. Use form paragraph 18.18 for lack of unity in U.S. national stage applications submitted under 35 U.S.C. 371.
Group , claim(s) , drawn to .
1. In brackets 1, 4 and 7, insert Roman numerals for each Group.
2. In brackets 2, 5 and 8, insert respective claim numbers.
3. In brackets 3, 6 and 9, insert respective names of grouped inventions.
This form paragraph may be used alone or following form paragraph 18.06.
This form paragraph may be used following either form paragraph 18.06 or 18.06.01.
Follow with form paragraphs 18.07.01 through 18.07.03, as appropriate.
 lack unity of invention because the groups do not share the same or corresponding technical feature.
1. This form paragraph may be used, for example, where the claims of Group I are directed to A + B, whereas the claims of Group II are directed to C + D, and thus the groups do not share a technical feature.
2. In bracket 1: For international applications in the international phase, identify the groups involved by Roman numerals (e.g., "Groups I and II") in accordance with the groups listed using form paragraphs 18.06 - 18.06.02. For U.S. national stage applications under 35 U.S.C. 371, identify the groups involved by Roman numerals (e.g., "Groups I and II") where inventions have been grouped using form paragraphs 18.06 - 18.06.02, or identify the species involved where species have been listed using form paragraph 18.20.
1. In bracket 1: For international applications in the international phase, identify the groups involved by Roman numerals (e.g., "Groups I and II") in accordance with the groups listed using form paragraphs 18.06 - 18.06.02. For U.S. national stage applications under 35 U.S.C. 371, identify the groups involved by Roman numerals (e.g., "Groups I and II") where inventions have been grouped using form paragraphs 18.06 - 18.06.02, or identify the species involved where species have been listed using form paragraph 18.20.
2. In bracket 2, identify the technical feature shared by the groups.
3. In bracket 3, insert citation of prior art reference(s) demonstrating the shared technical feature does not make a contribution over the prior art. Whether a particular technical feature makes a "contribution" over the prior art, and, therefore, constitutes a "special technical feature," is considered with respect to novelty and inventive step.
4. In bracket 4, explain how the shared technical feature lacks novelty or inventive step in view of the reference(s).
The phrase "significant structural element is shared by all of the alternatives" refers to cases where the compounds share a common chemical structure which occupies a large portion of their structures, or in case the compounds have in common only a small portion of their structures, the commonly shared structure constitutes a structurally distinctive portion in view of existing prior art, and the common structure is essential to the common property or activity.
The phrase "recognized class of chemical compounds" means that there is an expectation from the knowledge in the art that members of the class will behave in the same way in the context of the claimed invention, i.e. each member could be substituted one for the other, with the expectation that the same intended result would be achieved.
1. This heading should be used when the chemical alternatives of a Markush group are determined to lack unity of invention.
2. Follow with form paragraphs listed using form paragraphs 18.07.03a - 18.07.03c, as appropriate.
1. In bracket 1: For international applications in the international phase, identify the groups involved by Roman numerals (e.g., "Groups I and II") in accordance with the groups listed using form paragraphs 18.06 - 18.06.02. For U.S. national stage applications under 35 U.S.C. 371, identify the species involved where species have been listed using form paragraph 18.20.
2. In bracket 2, insert reasoning.
2. In bracket 2, identify common structure.
3. In bracket 3, insert citation of prior art reference(s) relied upon to demonstrate the commonly shared structure is not distinctive.
4. In bracket 4, explain why the compounds do not belong to a recognized class of chemical compounds.
PCT Administrative Instructions Section 502.
The International Searching Authority shall transmit to the applicant, preferably at the latest together with the international search report, any decision which it has taken under Rule 40.2(c) on the protest of the applicant against payment of additional fees where the international application is considered to lack unity of invention. At the same time, it shall transmit to the International Bureau a copy of both the protest and the decision thereon, as well as any request by the applicant to forward the texts of both the protest and the decision thereon to the designated Offices.
37 C.F.R. 1.477 Protest to lack of unity of invention before the International Searching Authority.
(a) If the applicant disagrees with the holding of lack of unity of invention by the International Searching Authority, additional fees may be paid under protest, accompanied by a request for refund and a statement setting forth reasons for disagreement or why the required additional fees are considered excessive, or both (PCT Rule 40.2(c) ).
(c) An applicant who desires that a copy of the protest and the decision thereon accompany the international search report when forwarded to the Designated Offices, may notify the International Searching Authority to that effect any time prior to the issuance of the international search report. Thereafter, such notification should be directed to the International Bureau (PCT Rule 40.2(c) ).
Protest of allegation of lack of unity is in the form of a reasoned statement accompanying payment of the additional fee, explaining why the applicant believes that the requirements of unity of invention are fulfilled and fully taking into account the reasons indicated in the invitation to pay additional fees issued by the International Searching Authority. Any such protest filed with the U.S. International Searching Authority will be decided by a Technology Center Director (MPEP § 1002.02(c) item (2)). To the extent applicant’s protest is found to be justified, total or partial reimbursement of the additional fee will be made. On the request of the applicant, the text of both the protest and the decision thereon is sent to the designated Offices together with the international search report (37 CFR 1.477(c) ).
A Notification of Decision of Protest or Declaration That Protest Considered Not to Have Been Made (Form PCT/ISA/212) is used by the Technology Center (TC) to inform the applicant of the decision regarding applicant’s protest on the payment of additional fees concerning unity of invention. The TC checks the appropriate box, i.e., 1 or 2. If box 2 is checked, a clear and concise explanation as to why the protest concerning the unity of invention was found to be unjustified must be given. Since the space is limited, supplemental attachment sheet(s) should be incorporated whenever necessary.
Form PCT/ISA/212 must be signed by a TC Director. See MPEP § 1002.02(c), item (2).
Under 37 CFR 1.475 and 1.499 et seq., when claims do not comply with the requirement of unity of invention, i.e., when the claimed subject matter does not involve "one or more of the same or corresponding special technical features," 37 CFR 1.475(a), an additional fee is required to maintain the claims in the same application. 37 CFR 1.476(b).
Nucleotide sequences encoding the same protein are considered to satisfy the unity of invention standard and will continue to be examined together.
Examples concerning Unity of Invention involving biotechnological inventions may be found in Chapter 10 of the International Search and Preliminary Examination Guidelines which can be obtained from the Patent Examiner’s Toolkit link or from the WIPO’s website (www.wipo.int/pct/en/texts/gdlines.html ).

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