Unit 2 Patent Application Preparation

Dependent claims regarding two-part claims and Markush claims

In the preceding examples, the dependent claims referred to an independent claim drafted in a conventional open-ended format. Let us now examine the situation in which a dependent claim refers to an independent claim written in the two-part form. By definition, a dependent claim referring to a two-part independent claim implicitly incorporates both sections of that independent claim.

In other words, it includes all elements stated in the preamble (the first part) as well as all elements appearing after the transitional expression “characterized in that” or “characterized by” (the second part). Consequently, the transitional expressions themselves (“characterized in that” or “characterized by”) are typically regarded as unnecessary in the dependent claim when it refers to a two-part independent claim, although their use remains permissible. The dependent claim will inherently include all limitations contained in both sections of the independent claim to which it refers.

Example
Claim 1 is drafted in the two-part format as:

A writing device, comprising: a pencil with two ends and an eraser attached to the pencil; characterized in that the eraser is attached to one end of the pencil.

A dependent Claim 2 that recites a light attached to the pencil as an additional element to the writing device in Claim 1 can be drafted as:
2. The writing device of Claim 1, further comprising a light attached to the pencil.

Where an independent Claim 1 is a Markush claim, a typical dependent claim may define a narrower subset of the Markush group presented in Claim 1.

Example
Using the example in section 2.3 of this module, a set of claims could read as follows:

A compound of the formula:

FIGURE 1

wherein

R1 is selected from the group consisting of H, C1-C3 alkyl, C3-C5 cycloalkyl and C1-C3 perfluoroalkyl;
R2 is … ; R4 is … ; R5 is … ; R6 is … ; and
R7 and R8 are each independently H, C1-C4 alkyl, (C1-C3 alkoxy)C2-C4 alkyl or hydroxy C2-C4 alkyl;
and pharmaceutically acceptable salts thereof.

The compound as claimed in claim 1, wherein R1 is selected from the group consisting of H, methyl or ethyl; R2 is C1-C3 alkyl; … ; R7 is… .
The compound as claimed in claim 2, wherein R1 is methyl; R2 is n-propyl; …

Claim 2 establishes a narrower scope than Claim 1 by specifying a more limited set of possible values for the radicals R1–R7. Claim 3 depends on Claim 2 and further restricts the Markush group.

3.3 Multiple Dependent Claims

Format and Structure of Multiple Dependent Claims

Multiple dependent claims constitute a particular category of dependent claims. The preamble of a multiple dependent claim refers to more than one independent claim and presents these references in the alternative. For instance, a multiple dependent claim may read, “the apparatus of Claim 1 or Claim 2” or “the apparatus of one of Claims 1 and 2.” Such wording signifies that the claim may depend on either Claim 1 or Claim 2, but not on both at the same time.

As with standard dependent claims, the body of a multiple dependent claim must also narrow the scope of the claims to which it refers. In other words, it cannot extend or broaden the scope of the claim; instead, it introduces additional limitations or characteristics that further define the apparatus in relation to the selected claim.

Example
Recall our pencil:

An apparatus, comprising: a pencil and a light attached to the pencil.
The apparatus of Claim 1, wherein the light is detachably attached to the pencil.

Here, an additional claim drafted in the multiple dependent claim format may be written as:
3. The apparatus as recited in Claims 1 or 2, further comprising an eraser.

This multiple dependent Claim 3 covers an apparatus comprising either

a light attached to the pencil and an eraser; or
a light detachably attached to the pencil and an eraser

Therefore, for an accused apparatus to infringe this claim, it must include either of these sets of limitations.
In practice, a patent drafter may choose to draft a claim set using only single dependent claims or, alternatively, by employing multiple dependent claims.
The following two claim sets are equivalent in terms of both claim scope and the level of protection they provide.

Example
Alternative A, using a multiple dependent Claim 3:

An apparatus, comprising: a pencil and a light attached to the pencil.
The apparatus of Claim 1, wherein the light is detachably attached to the pencil.
The apparatus of Claims 1 or 2, further comprising an eraser.

Alternative B, using only single dependent Claims 2-4:

An apparatus, comprising: a pencil and a light attached to the pencil.
The apparatus of Claim 1, wherein the light is detachably attached to the pencil.
The apparatus of Claim 1, further comprising an eraser.
The apparatus of Claim 2, further comprising an eraser.

A claim tree can visually illustrate the relationships between a multiple dependent claim, an independent claim, and single dependent claims.

Our example can be drawn as:

Figure 3

Here, “3/1” and “3/2” indicate that Claim 3 is a multiple dependent claim depending from Claim 1 or Claim 2; therefore, 3/1 branches from Claim 1 and 3/2 branches from Claim 2.
To refer to more than one claim in the alternative within a multiple dependent claim, several other expressions are commonly accepted across many jurisdictions, such as:

“A pencil according to Claim 1 or Claim 2, wherein…”
“A pencil as in either Claim 1 or Claim 2, further comprising…”
“A pencil as in any one of Claims 1, 3 or 9-13 inclusive, in which…”
“A pencil as in any of Claims 1, 4, 5-7 in which…”
“A pencil as in any of Claims 2 or 3, further comprising…”
“A pencil as in any of the preceding claims in which…”

To preserve clarity and prevent ambiguity, wording that results in cumulative dependency is not allowed. Examples of such impermissible formulations include: “according to Claims 1 and 2,” “according to Claims 1-3,” or “as in Claims 1, 2 and/or 3.” These expressions indicate dependence on all listed claims simultaneously, which conflicts with the alternative structure required for multiple dependent claims.

Pros and cons of multiple dependent claims

The use of multiple dependent claims presents both strategic benefits and potential drawbacks, particularly in relation to claim fees and drafting flexibility.

Pros:

Reduced Claim Count: In general, employing multiple dependent claims can decrease the total number of countable claims. This may be advantageous for applicants when considering the overall cost of a patent application.
Consolidated Grouping: It can be more practical to organize related dependent claims together within a single multiple dependent claim framework.

Cons:

Claim Fee Implications: The effect on claim fees differs considerably depending on the jurisdiction:
United States: In the United States, multiple dependent claims frequently incur additional claim fees, which makes them less commonly used in routine drafting practice.
European Patent Office (EPO): In contrast, at the EPO the use of multiple dependent claims may lead to cost savings. This is because the EPO calculates claim fees based on the number of numbered claims (e.g., Claim 1, Claim 2, etc.). Drafting the equivalent scope using only single dependent claims could significantly increase the total cost.

Other Considerations:

New Matter Restrictions: An important principle in patent law is the prohibition against introducing “new matter” during the amendment process. In certain jurisdictions, including the EPO, the use of multiple dependent claims may offer a stronger basis for amendments in particular circumstances. This approach can facilitate claim amendments because the application as originally filed already encompasses a broader scope containing various alternatives.

Let us examine an illustrative example to clarify these concepts further.

Example
A claim set includes only single dependent claims:

Claim 1. A composition, comprising: an element A selected from the group consisting of A1 and A2; and an element B selected from the group consisting of B1, B2 and B3.
Claim 2. The composition according to Claim 1, wherein A is A1.
Claim 3. The composition according to Claim 1, wherein A is A2.
Claim 4. The composition according to Claim 1, wherein B is B1.
Claim 5. The composition according to Claim 1, wherein B is B2.
Claim 6. The composition according to Claim 1, wherein B is B3.

An examiner identified prior art references covering the various combinations of elements A and B, except for the combination of A1 and B3, and the applicant now intends to amend the claim as:

[new] Claim 1. A composition, comprising: element A1; and element B3.

Unless the application as filed contains a specific disclosure relating to this particular combination, such an amendment at the EPO would likely be objected to on the basis that the selection of these two characteristics is not clearly and unambiguously derivable from the application as originally filed. However, according to EPO case law, this objection would not arise if there were a dependent claim explicitly directed to a composition comprising elements A1 and B3.

Unfortunately, the above set of six claims does not recite this particular combination.

If multiple dependent claims had been used, however, the applicant could have covered various combinations within the same number of claims:

Claim 1. A composition, comprising: an element A selected from the group consisting of A1 and A2; and an element B selected from the group consisting of B1, B2 and B3.
Claim 2. The composition according to Claim 1, wherein A is A1.
Claim 3. The composition according to Claim 1, wherein A is A2.
Claim 4. The composition according to any one of Claims 1–3, wherein B is B1.
Claim 5. The composition according to any one of Claims 1–3, wherein B is B2.
Claim 6. The composition according to any one of Claims 1–3, wherein B is B3.

Claim 6, insofar as it refers back to Claim 2, covers the specific combination of elements A1 and B3.

Having numerous claims drafted in the multiple dependency format can also be advantageous for a patent proprietor. It may allow them to amend their claims more easily in situations where a third party challenges the validity of a granted patent, or when they wish to voluntarily restrict the scope of protection, for example to a very narrow (and very robust) claim that protects the only commercial product likely to be imitated. In such circumstances, however, claim amendments are permissible only if they do not extend the protection conferred by the granted patent.

This can be illustrated by considering how our two groups of six claims, one without and the other with multiple dependencies, might influence a nullity action.

Example
Let us assume that the only embodiment of interest is “Preamble-P comprising A1 and B3” (e.g., the only active pharmaceutical ingredient authorized for sale, which is the only one competitors seek to exploit).
In a nullity action, a prior art document disclosing “Preamble-P comprising A2 and B3” would destroy the novelty of Claim 1 and Claim 6 of the first claim set, thereby invalidating the two granted claims that protect the embodiment of interest.
However, that same prior art document would not destroy the novelty of Claim 6 of the second claim set when dependent on Claim 2. That specific claim would read “Preamble-P comprising A1 and B3” and would explicitly protect the embodiment of interest.

Professional tip
Keep in mind that multiple-multiple dependent claims increase the complexity of a patent application. If they are used excessively or without necessity, the resulting claims may combine features from numerous referenced claims, making them difficult to understand.

Multiple-multiple dependent claims

Up to this point, all examples of multiple dependent claims have referred back either to an independent claim or to a single dependent claim. However, can a multiple dependent claim itself serve as the basis for another multiple dependent claim? In some jurisdictions, such as the EPO and Japan, this is permitted, whereas in others, such as the United States and the Republic of Korea, it is not.

Claim 4 below illustrates such a multiple-multiple dependent claim:

Claim 1. An apparatus, comprising: a pencil and a light attached to the pencil.
Claim 2. The apparatus of Claim 1, wherein the light is detachably attached to the pencil.
Claim 3. The apparatus of Claims 1 or 2, further comprising an eraser.
Claim 4. The apparatus of any one of Claims 1-3, wherein the light is an LED light.

3.4 Claims Referring to Features of Another Claim

In certain jurisdictions, including the European Patent Office (EPO), an independent claim may refer to another claim and thereby incorporate the features defined in that claim without being regarded as a dependent claim. This situation may arise when the claims belong to different categories. For example:

A claim may read, “Apparatus for carrying out the process of Claim 1…,” allowing it to refer to the features of the process claim while remaining an independent claim.
In a situation involving a plug and socket, a claim directed to the plug might state, “Plug for cooperation with the socket of Claim 1…,” thereby incorporating the features of the socket claim without being treated as a dependent claim.

However, in other jurisdictions, such as the United States, independent claims are not permitted to refer to any other claim. This distinction highlights the importance of understanding the specific claim-drafting rules that apply in each jurisdiction.

When drafting claims that refer to features defined in other claims, it is essential to carefully examine those incorporated features to determine whether they are essential to the invention being claimed. The patent drafter must ensure that this approach to referencing claims complies with the legal requirements of the jurisdictions in which patent protection is sought.

A definitional reference to another claim is particularly common in claims relating to computer-implemented inventions. This technical field often requires the drafting of multiple claim types including claims directed to methods, apparatuses, computer program products, and computer-readable storage media to ensure comprehensive protection of the invention. In such cases, referential claims help clearly define the relationship between the different aspects of the invention and thereby reinforce the breadth of protection.

Example
A computer-implemented method Claim 1 recites the essential steps (i)- (x). A claim directed to a data-processing apparatus may read:
2. A data-processing apparatus comprising means for carrying out the method as defined in Claim 1.

Similarly, a computer program product claim may read:
3. A computer program product comprising instructions which, when the program is executed by a computer, cause the computer to carry out the method as defined in Claim 1.

This type of reference to another claim also appears in the pharmaceutical field, where several different types of claims are typically provided, such as claims directed to a new chemical compound, a pharmaceutical composition comprising that compound, and a method for manufacturing the compound.

Example
Claim 1. A compound of the formula:
wherein

R1 is selected from the group consisting of H, C1-C3 alkyl, C3-C5 cycloalkyl and C1-C3 perfluoroalkyl;
R2 is … ; R3 is … ; R4 is … ; R5 is … ; R6 is … ; and
R7 and R8 are each independently H, C1-C4 alkyl, (C1-C3 alkoxy)C2-C4 alkyl or hydroxy C2-C4 alkyl;
and pharmaceutically acceptable salts thereof.

Claim 2. A compound as claimed in Claim 1, wherein R1 is selected from the group consisting of H, methyl and ethyl; R2 is C1 C3 alkyl; […].
Claim 3. A compound as claimed in Claim 2, wherein R1 is methyl; R2 is n-propyl; […].
Claim 4. A compound as claimed in Claim 3, wherein the compound is selected from [seven systematic chemical names]; and pharmaceutically acceptable salts thereof.
Claim 5. A pharmaceutical composition comprising a compound of the formula (I) or a pharmaceutically acceptable salt thereof, as defined in any one of Claims 1-4, together with a pharmaceutically acceptable diluent or carrier.
Claim 6. A compound of the formula (I) or a pharmaceutically acceptable salt thereof, as defined in any one of Claims 1-4, for use in medicine.
Claim 7. A use of a compound of the formula (I) or a pharmaceutically acceptable salt thereof, as defined in any one of Claims 1-4, for the manufacture of a medicament for the treatment of angina, hypertension and […].
Here, Claims 1-4 relate to compounds of specific formulae “and pharmaceutically acceptable salts thereof.” Claim 5, which concerns a pharmaceutical composition, refers to the features of “any one of Claims 1-4.” As a result, a single Claim 5 incorporates the features of each of Claims 1-4 through a multiple reference. Likewise, by making a multiple reference to Claims 1-4, Claim 6 covers the first medical use of the compound, while Claim 7 relates to a second medical use of the compound.

By employing references to the features of multiple claims, the overall number of claims can be significantly reduced.

Figure 4

In certain jurisdictions, including the European Patent Office (EPO), a particular relationship exists between process claims and product claims. If a claimed process produces a product that is itself defined in a product claim, and if that product claim is considered patentable, a separate assessment of novelty and nonobviousness for the process claim may not be necessary. This exemption applies provided that all features of the product, as defined in its claim, are necessarily and inevitably obtained by the claimed process.

This principle also applies to claims directed to the use of a product. When the product itself is patentable and is employed in accordance with its claimed features, a claim relating to its use may likewise not require an independent examination of novelty and nonobviousness.

It should be emphasized that in all other circumstances, the patentability of a referenced claim does not automatically ensure the patentability of the independent claim that refers to it. Accordingly, careful attention must be given to the specific characteristics and essential features of each claim during both the drafting and examination of patent applications.

The Secretariat of WIPO assumes no liability or responsibility with regard to the transformation or translation of the original content. World Intellectual Property Organization (WIPO) (2023). WIPO Patent Drafting Manual, Second edition. Geneva: WIPO. DOI: 10.34667/tind.44657