How Much Is Enough? Sufficiency and Working Examples in Indian Patent Practice

Summary: This analysis examines how Indian courts evaluate “sufficiency of disclosure” in patent applications. Focusing on the role of working examples, it highlights judicial standards for determining whether a specification enables a person skilled in the art to replicate the invention, drawing on decisions from various High Courts across India.

Introduction

The monopolistic rights granted under a patent are a quid pro quo for disclosures made by the inventor. In other words, in exchange for a time-limited monopoly, the inventor is expected to disclose the invention in a manner sufficiently clear and complete for a person skilled in the art (PSITA) to perform it without undue experimentation.

In this context, a question often asked is, how much disclosure is considered “sufficient”. The answer lies in both the volume and extent of the description. This leads us to the concept of ‘working examples’ contained in a specification.

Working examples are illustrative embodiments or examples provided in a specification, and seek to assist a PSITA in understanding how the invention operates and may be performed. More often than not, working examples are deemed a requirement by the Indian Patent Office (IPO) in patent applications.

This note discusses some recent decisions discussing the requirement of sufficiency of disclosure and the necessity (or otherwise) of accompanying working examples.

Legal basis

The term “working example” is neither defined nor mandated as a requirement under the Patents Act, 1970 (the Act); the Patents Rules, 2003 (the Rules); or the Manual of Patent Office Practice and Procedure (MPPP).

Some guidance, however, can be gleaned from Section 10, which delineates the contents of a specification. Among other things, a specification must:

• “fully and particularly describe the invention and its operation or use and the method by which it is to be performed” (Section 10(4)(a));
• “disclose the best method of performing the invention which is known to the applicant” (Section 10(4)(b)); and
• include claims that are “fairly based on the specification” and that are “clear, succinct and definitive” (Section 10(5)).

Relatedly, section 05.03.09(a) of the MPPP states:

“Description of an invention is required to be furnished in sufficient detail so as to give a complete picture of the invention and follows the Summary of invention. The nature of improvements or modifications effected with respect to the prior art should be clearly and sufficiently described. It may include examples/drawings or both for clearly describing and ascertaining the nature of invention. Examples must be included in the description, especially in the case of chemical related inventions.” [emphasis added]

Judicial context

Indian courts have regularly emphasised strict compliance of Section 10(4) and (5) of the Patents Act, calling for enabling and robust disclosures.

Landmark decisions (e.g., Bayer Pharm Aktiengesellschaft versus The Controller General of Patents and Designs (Delhi High Court; C.A.(COMM.IPD-PAT) 255/2022) and Titan Umreifungstechnik GmbH vs Assistant Controller of Patents and Designs (Delhi High Court; C.A.(COMM.IPD-PAT) 114/2022)) suggest that while working examples can help assess if the disclosure enables the invention, they are not mandatory, especially for non-chemical inventions, where drawings, descriptions, steps, or explanations may sufficiently enable a PSITA to perform the invention.

A logical inference would be to consider the need for working examples as being technology-dependent. Recent decisions shed more light on the working example requirement in inventions in different technological areas, some of which are discussed below:

(I) Chemical, Pharmaceutical and Biochemical Inventions:

• The Regents of the University of California v. The Controller of Patents (Delhi High Court; C.A. (COMM.IPD-PAT) 481/2022): The claims covered within their scope “loss of function” of a certain gene (achieved by mutations). However, the claims enabled only “deletion” type mutations to achieve this, and not “insertion” and “substitution” type mutations. The Court held the complete specification insufficient as it did not enable all the claimed embodiments (i.e., no data or examples for insertion and substitution mutations was provided).
• Amgen Inc. v. Assistant Controller of Patents & Intas Pharmaceuticals(Madras High Court; CMA(PT) No.28 of 2023): The Indian Patent Office (IPO) had refused the patent application for, among other grounds, insufficient disclosure, as the experimental data supported only one sequence out of 52 peptibody variants covered by the broad claim. The Court held that, given the complexity and variability of amino acid sequences, sufficiency was met only for the embodiments with supporting data, and the patent grant was accordingly narrowed.
• Fraunhofer Gesellschaft Zur Forderung Der Angewandten Forschunge vs The CGPDTM (Calcutta High Court; IPDPTA/11/2024): Upholding the IPO’s refusal, the Court found the specification to be “shooting in the dark”, and based on trial and error, as it described infinite range of time interval (“minutes to months”) and claimed open ended ranges (“maximum of 10%”), without any operative experimental parameters or working examples. The Court brusquely observed, “The specification altogether is essentially It describes functional results and gives open ranges which would necessarily lead to excessive experimentation and uncertainty.”

(II) Computer Related Inventions:

1. Caleb Suresh Motupalli v. Controller of Patents (Madras High Court; M.A. (PT) No. 2 of 2024): The Court observed that although a specification need not disclose every detail with perfect precision, it must not require undue experimentation or the use of inventive faculty by a PSITA. Here, the complete specification referred to “standard techniques for integration”, but did not provide any working examples of how those techniques would achieve the promised integration. The decision, however, was appealed and is pending adjudication in the Supreme Court of India.

   Meanwhile, citing this judgement, the Guidelines for examining Computer Replated Inventions (CRIs), 2025, provide a framework for meeting sufficiency requirements for artificial intelligence / machine learning  (AI/ML) inventions, and recommend that the specification must include training data sets, model architecture, etc.

2. Arti Srivastava vs The Assistant Controller of Patents (Delhi High Court; C.A.(COMM.IPD-PAT) 252/2022): The Court observed that the specification of the claimed invention, for detecting counterfeits through a dual code verification mechanism, only described the modes of transmission of codes and missed essential working details such as transmission, verification, storage, etc. The Court found the accompanying flowcharts and diagrams insufficient, noting that such details cannot be left to the PSITA to construe, who would then have “to further research to make the invention work”.

Key takeaways

In summary, working examples or experimental data may be included in a specification to serve the following ends:

1. to demonstrate the invention’s operability across the claimed scope;
2. to enable a PSITA to work/perform the invention without requiring further research or experiments; and
3. to support the claims.

Working examples may be in any form, including exemplary data demonstrating the working of invention, experimental data, flowcharts, algorithms, process parameters, or other implementation details, depending on the technological field of the invention.

The requirement is not statutorily mandated. But it more relevant than not in fields such as biotechnology, pharmaceuticals, and artificial intelligence/machine learning (AI/ML), where results depend on specific inputs, model architecture, training datasets, parameters, or experimental conditions. For AI/ML inventions, especially those involving black-box models, disclosures must not only name a standard technique, but also explain how the claimed technical effect is achieved in the claimed implementation.

In contrast, for mechanical inventions, drawings and descriptions explaining the invention’s working can be sufficient.

Conclusion

Even as there might be variance across technical fields, the essentials of the sufficiency requirement remains the same for all inventions, i.e., the specification should set out both “what” the invention is by describing it fully and particularly, and “how” to perform it by disclosing the best method known to the applicant.

Some practical challenges persist, e.g., the absence of a statutory definition of a PSITA. Controllers or Examiners in the IPO cannot be deemed PSITA, especially where a claimed invention is in an underlying technology that is rapidly evolving or requires niche expertise. This inevitably invites subjective assessments of enablement.

Separately, attempts to secure broad claim scope without disclosure support often results in claim narrowing and increased prosecution costs. There is also limited opportunity to remedy deficiencies after filing (here, it is useful to treat sufficiency as a filing-stage strategy, and not a prosecution-stage repair exercise).

Cumulatively, therefore, it becomes all the more important to ensure that specifications are drafted with technical detail and foresight from the outset.