Trademarks have over time, distinguished themselves as the popular kids among the Intellectual Property rights. This is so because they are perhaps the most protected amongst the bundle of IP rights and well, inevitably the face of your business. A trademark builds your brand value by rendering it exclusive, by distinguishing your business from the millions of competitors that emerge in the market every single day.

When one sets forward to register his mark, he must persevere at every step of the examination process, and ensure that every document, every argument, and every claim has adequate substantiation. This is where the concept of prosecution history estoppel factors in.

What does the Doctrine mean?

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The doctrine of prosecution history estoppel is popularly associated with patent litigation. In the context of patents, the doctrine constitutes a legal defence to an assertion of infringement whereby the Examiner determines the scope of infringement by examining if there is an overlap between the elements of the impugned products/process in light of the claims of patent, rather than a literal infringement of the same. Although not as apparent as in patent prosecution, prosecution history estoppel does apply to trademarks as well, predominantly in the case of relative grounds of refusal. The doctrine of equivalents in trademarks, constitutes a preventative measure exercised by the examiner while examining trademark applications.  Any response to the objections cited can then be cited for an assertion of infringement or otherwise, in an infringement proceeding.

The Doctrine in the Indian regime

This doctrine has seldom been exercised by the Indian courts in light of trademarks in adjudicating a trademark infringement, except for a few wherein the reliance on prosecution history was explicitly brought out in the judgement.

In Mankind v Chandran Mani Tiwari and Anr., the plaintiffs were successful in restraining the defendants from using the mark MERCYKIND, as they were able to place reliance on the examination response filed by them listing out that they are the proprietors of a family of marks ending with the suffix ‘KIND’ by virtue of which the mark as such has obtained synonymity with the plaintiffs, with adequate evidence substantiating the same.

In Bata India Ltd v. Chawla Boot House,  the Delhi High Court expressly noted the contradictions stated by the defendants through a comprehensive examination of the prosecution history of both the Plaintiffs and the defendants, ruling in favour of the plaintiffs to the extent of such contradictions.

That being said, although the prosecution history estoppel is a brilliant defence that aids in the assertion of infringement in the case of prior users, it is also pertinent to note that any statement made in trademark prosecution in any manner whatsoever is a double-edged sword. The popular method to overcome relative grounds of refusal is to put forward assertive arguments to avoid any scope of confusion between the cited marks and one’s subject mark. In lay terms, any statement you make to the registrar in writing can be used against you in a suit of infringement.

In a recent case Keller Williams Realty, Inc. v. Dingle Buildcons Pvt. Ltd. & Ors., the Delhi High Court ruled against the claimant in respect of the ex-parte injunction sought against the defendants for their use of the mark ‘KW’, partly relying on the prosecution history defence adopted by the defendants. The defendants therein identified that the claimants denied that the goods and services covered by the marks are similar in a response to the examination report and claimed otherwise in the suit of infringement. 


Here comes a question- why not institute an opposition against every mark cited in an examination report? When certain marks are cited in the examination report, oftentimes they remain in pre-advertisement stage and they often deal with a narrow range of goods and services. With this handicap, the easiest way to overcome the objection is to distinguish between the marks or its class of goods. Furthermore, oppositions are an expensive ordeal, not to mention the time taken to reach the close of the proceedings even if one is instituted. With a suit of infringement, an immediate remedy (injunction) against the defaulting party can be sought.  This being said, it is also relevant to factor in the time consumed in processing trademark applications as well. Within the time that passes between filing the response to registration of the mark, the cited mark would have built its business to an extent that causes a substantial infringement of the subject mark, which in the meantime would have attained substantial recognition in the market.


Hence, while drafting examination responses, it would be advisable to factor in the future of their client’s business as well as that of the cited marks. In the case of prior users, domestic or otherwise, in many cases, it may be ideal to focus on the usage claim and evidence rather than bringing out the differences between the cited marks and itself.  This would prove to be suit of armour, protecting your business against anyone who seeks to tarnish its goodwill.

However, this theory would seldom apply to International applications. Madrid system has an unfortunate glitch, whereby the user detail is perpetually appended as proposed to be used, even if the mark has a long-standing use in India. The evidence of use can only be asserted through a response to the examination report, if one is issued. There is no provision to update the use claim elsewhere.  This gives domestic businesses an upper hand, even if temporary since they can rely on the prosecution history and rely on a use claim.

A provision for international marks to claim usage through Madrid system would resolve the issue. Meanwhile, as far as practicable, it is probably the best to exercise caution in a trademark examination process and devise strategies in light of the prosecution history estoppel. You know what they say, ‘better safe than sorry!’.

This article has been authored by Drisya R