Dupe or Infringement? Where Should the Law Draw the Line in Fashion?

Exploring the legal boundary between fashion inspiration, imitation and intellectual property infringement

Key Takeaways: A “dupe” is not a legal term; it has no independent meaning in the law, and whether a “dupe” is legal depends entirely on what sort of intellectual property right, if any, may exist to protect the design. In 2026’s Deckers v. Quince, the split jury verdict demonstrates this perfectly, the jury found the design to be sufficiently similar to infringe, and separately found the underlying patent invalid, rendering no such right available to support infringement in the first place. India gets the same result through different doctrine, the “fifty-copy rule” of the Copyright Act’s Section 15(2), designs registration and the common law tort of passing off.

I. The Question

Each new fashion season sees the appearance of many more “dupes”, less expensive reproductions of expensive products, sold openly and marketed as such. Social media has created its own subgenre of “dupe hunting.” Brands call dupes theft. Dupe-sellers call them competition. The law is caught in the middle; and the law does not take a side. For this reason, because “dupe” describes only a marketing strategy, not a legal concept, the law has not been able to answer the question posed.

Instead of asking whether dupes are legal, this article addresses a more limited question – what makes lawful fashion inspiration into intellectual property infringement? The jury verdict from June 2026, Deckers Outdoor Corp. v. Last Brand Inc.[¹], the “dupe” case against Quince provides an interesting case study, because it forces the question into its sharpest possible form. In Deckers v. Quince, a jury found that Quince’s product design was substantially similar to Deckers’ patented design and further found the patent invalid making clear that there could be no intellectual property right available to support infringement.

II. What a “Dupe” Actually Is

The term “dupe” can refer to several things. Here is a quick summary of four distinct terms and the different legal consequences of each.

A counterfeit duplicates a product’s trademark or something very like it, “UGG” sewn into a boot Deckers never made. Trademark counterfeiting generally constitutes trademark infringement where the counterfeit mark satisfies the applicable legal requirements, and may attract civil as well as criminal penalties depending on the jurisdiction.

The term knockoff refers to a product designed to imitate another in appearance but using none of the latter’s brand names or trademarks. The boots produced by Quince can be considered a knockoff in this strict meaning of the term because they resemble UGGs yet lack anything like a trademark or a brand name on the product.

A dupe is a knockoff openly advertised in connection with the product imitated. In other words, the product will explicitly say “if you love the UGG Mini, you’ll love ours” or something similar.

By themselves, none of these three terms allows for determining the legal status of the product: whether the imitating product infringes some IP rights. This depends totally on the type of rights (or their absence) protecting the feature that is being imitated. One product can look almost the same as another but still not infringe the latter’s IP, simply because the similarities are related to those features of design that are not subject to protection by the law (functional shape, common design, expired design). Another product can look very differently and still infringe someone else’s rights, simply because it imitates a particular feature of design or technology that is protected by the law.

III. IP Protection in Fashion Design

Fashion is subject to a variety of distinct areas of law. These each cover something else and disputes about whether the relevant protection applies turn on whether one area of law is applicable at all to the feature at issue.

Copyright covers creative, original expression, in particular, a print, embroidery pattern, fabric design, sketch, etc. In most instances, copyright does not apply to the cut of a garment because clothes are considered “useful articles” in US law, and the configuration is therefore not copyrightable unless some element of the design is separable from the function of the useful article. Indian law arrives at a similar result through a different path, namely Section 15 of the Copyright Act, which is covered in Part V below.

Trademarks cover source identifying indicia which is usually a name or logo and sometimes packaging, for use against any use likely to confuse consumers as to source.

A form of trademark law, trade dress, or, in India, the UK and elsewhere, passing off, may cover a product’s overall appearance, but only if it is relied upon by consumers to determine source of the product. There are two distinct doctrines which can prevent trade dress protection, and they are not the same analysis. One feature may be considered generic, meaning that it is merely common to the industry, rather than being distinctive of any individual manufacturer. A design is said to be functional if it is developed for a reason that makes it more efficient rather than because it is used as a means to signal brand identity. Under US law, once a patent has expired, disclosure of its features in the utility patent is very strong evidence that it is functional and not protected under trade dress even if consumers rely heavily on it as a source indicator.[²⁰]. Either failing point is sufficient grounds for dismissal in its own right – in the case of Deckers, the trade dress claims failed for lack of distinctiveness (genericness), while the court also took the opportunity to note that Deckers had failed to demonstrate its case regarding functionality as well. According to Indian law, passing off entails proving three elements: reputation or goodwill attributable to the trade dress in question, false representation that would deceive consumers, and actual or potential harm done to this reputation.[¹⁵] Indian courts have held that the action for passing off does not require any trademarks to be registered, and protects reputation acquired through a good name even when it was built up in other jurisdictions than India.[¹⁶]

Design patents (U.S. terminology) offer protection for a limited time to the ornamental features of an item, as long as they were novel and non-obvious relative to prior art at the time of application, the novelty and non-obviousness test used for utility patents but adapted for design patents. The test for infringement is based on the ordinary observer test established by the U.S. Supreme Court in 1871 in Gorham Co. v. White, and later clarified by the Federal Circuit sitting en banc in Egyptian Goddess, Inc. v. Swisa, Inc..[¹⁸][¹⁹]. In India, registered designs, as defined in the Designs Act 2000 [13], provide protection for similar concepts, but under a slightly different test for registrability: a design is registrable only if it is new or original, not previously made available to the public, and is significantly distinguishable from known designs and combinations thereof.[¹³] The test for what constitutes “new or original” in this context according to the Indian Supreme Court is if the design has never been previously published or otherwise made known to the public, and never been reproduced before.[¹⁷] An Indian registered design offers protection for a period of ten years, renewable for another five, giving fifteen years altogether as the maximum protection, and not the vague “ten-to-fifteen-year” range. The U.S. right on which Deckers relied when claiming the UGG Classic Ultra Mini is the design patent, protected by the ordinary observer test, not the Indian design patent, and this is the right on which the jury found against Deckers.

Counterfeiting is distinct from ordinary imitation because it involves the unauthorised use of a mark that is identical or substantially indistinguishable from a protected trademark. The consequences may include civil remedies and, in some jurisdictions, criminal liability.

Differences and overlapping areas of these systems are where the majority of duping cases take place. One can fail to prove both trade dress and design patent infringement in one and the same product without this indicating that there is no protection for fashion IP at all, it only shows that these two systems do not apply to this particular design.

IV. Case Study: Deckers Outdoor Corp. v. Last Brand, Inc. (Quince)

Deckers Outdoor Corp. v. Last Brand, Inc. d/b/a Quince was commenced on June 12, 2023, in the United States District Court for the Central District of California, but was later transferred to the United States District Court for the Northern District of California in September 2023 under case number 4:23-cv-04850-AMO, presided over by Judge Araceli Martínez-Olguín. In an amended complaint, Deckers Outdoor alleged unregistered trade dress infringement in connection with the Classic Ultra Mini boot, the Bailey Button boot, and the Tasman slipper, as well as infringement of U.S. Design Patent No. D927,161 on the Classic Ultra Mini boot’s upper, silhouette, and surface.

Both parties filed motions for summary judgment. Deckers Outdoor claimed that the three trade dresses in question are non-functional and have secondary meaning due to their commercial success, press coverage, and consumers’ recognition and provided evidence attempting to demonstrate that Quince started from using the pictures of popular UGG models as a basis for their own design. For its part, Quince claimed that the Classic Ultra Mini and the Tasman trade dresses are generic, that is, they are common throughout the footwear industry, not specific to UGG. This company cited over a dozen competitors offering similar boots and several others offering similar slippers.

Judge Martínez-Olguín ruled mostly in favor of Quince regarding the trade dress claims. She ruled that Deckers had failed to prove that the Classic Ultra Mini and the Tasman were non-generic in terms of trade dress. In addition, she rejected Deckers’ argument that distinctiveness could be established merely by showing that there have been no similar products before UGG created its line and ruled that Deckers had not satisfied the requirement that trade dress be aesthetically functional.

The design patent claim also survived the summary judgment stage. According to the court, Quince’s argument related to the functionality of the design was not persuasive enough and its indefiniteness argument was not strong enough either. The same can be said for the Bailey Button trade dress claim, which was prevailing at that point.

By the time of the June 2026 trial, the Classic Ultra Mini and Tasman trade-dress claims had already been dismissed, leaving the design patent claim for trial.

The trial lasted for four days. Counseling the jury, Deckers’ attorney, Brent Blakely, asserted that Quince could have made any kind of boot it wanted, but it opted for one that looked almost identical to the patented design. Xinlin Li Morrow, the attorney at Law for Quince, contended that Deckers was utilizing the design patent to create a monopoly in the entire category of sheepskin boots, as the patent covers features that are typically incorporated into the whole category. In February 2026, separate from the patent case, Quince filed an antitrust lawsuit against Deckers pursuant to Section 2 of the Sherman Act, charging that Deckers was employing patent litigation abuses in order to take over standard shoewear features in the whole business.

The jury was asked two questions: whether, from the perspective of an ordinary observer – the test formulated by the Supreme Court in Gorham and upheld by the Federal Circuit in Egyptian Goddess[19], Quince’s boot resembled very closely the patented design overall, and whether the patent was valid, considering how developed the market for shear­ling boots is and how many manufacturers are operating there. The jury decided after only two hours of deliberation that Quince had infringed the patent but the patent itself was invalid, something the public was quick to interpret as a victory for Deckers in spite of the fact that a patent being invalid means it cannot be enforced in any way. Whether the case was a win or a loss for Deckers matters little, though, because an invalid patent is worthless and cannot bring any return to its owner.

The basis for the assertion of invalidity is not completely clear, contrary to some of the earliest reports. The jury was given instructions on two possible theories for invalidity: obviousness based on the prior art and functionality of elements of the design. What distinguishes this case is that the verdict form itself was of very general nature and did not require the jury to indicate its basis for the conclusion on the invalidity of the design patent. This is important because obviousness and functionality are two different legal defenses each with its own specific requirements that could impact the outcome in the appellate court. The conclusion is known, but the reasoning behind it remains unclear.

The crucial importance of the decision arises from the information gained on the effectiveness of using two different intellectual property rights is the same product. The trade dress claim was unsuccessful due to the fact that the design was generic and because Deckers failed to show the utility of the design. The design patent claim did not win the trial, as the jury ruled that it is invalid for some reason or reasons, which have not been revealed in the court records. It is noted in a commentary afterwards that the invalidity of design patents is typical in case of product categories full of similar designs, and it is difficult to prove that this design was new among the others. In conclusion, the results indicate that some aspects of the product design are too commonplace or functional to make them exclusive for a certain brand.

This is the takeaway from the case and it’s not a lesson that copying is permissible overall. The real lesson to learn here is the difference between commercial branding and legal protection. It is one thing for consumers to associate a look with UGG but that does not give UGG a monopoly over that look in legal terms. A business that wants to stop copycats must have a legal right that has been properly established and protected.

V. The View from India

While India does not yet have an equivalent case to Deckers-Quince, its legislative framework is likely to see the case dealt with under different legal principles due to the relationship between the Copyright Act, 1957 and the Designs Act, 2000.

The primary reference is Section 15 of the Copyright Act.[8] The first subsection states that copyright does not exist regarding the design that has been registered under the Designs Act. The second subsection is the more significant clause regarding copyright in fashion: where the design is subject to the registration but was never actually registered under the Designs Act, copyright ceases after the article containing it has been produced more than fifty times by industrial means; that is the “fifty-copy rule.” This is an attempt to limit designers from gaining protection with the help of copyright protection, which lasts for the duration of the author’s life plus sixty years in India and using that as an excuse for protecting the design for a much greater term than the fifteen-year maximum limit stipulated by the Designs Act for registered designs once the design has been transformed from a piece of art to being manufactured in large volumes on the market.

This provision has led to actual litigation. In Ritika Private Limited v. Biba Apparels Private Limited (decided on March 23, 2016),[⁹] Ritika, which operates the RITU KUMAR brand, brought a legal case against Biba for violations of copyright with respect to garment patterns and designs. Biba made a plea to have the case dismissed under Order XII Rule 6 of the Civil Procedure Code contending that there was no ground for the claim as Ritika had already admitted that its designs had been used in making over fifty garments. Justice Valmiki J. Mehta noted that when a design is made which can be registered under the Designs Act and crosses over fifty copies in production then no copyright protection can be claimed irrespective of whether the design was registered. The court was of the opinion that it was confined by the ruling of the earlier Division Bench in the case of Microfibres Inc. v. Girdhar & Co. & Anr. (decided on May 28, 2009)[¹⁰] in which a similar decision was taken with reference to patterns of fabrics in upholstery. The Division Bench formulated the core policy dilemma in precise terms: the objective of Section 15(2) is not to prevent copying in itself, but rather to prevent the right holder from being able to use copyright’s longer duration to set up an exclusive monopoly, which has been purposefully restricted by the Designs Act to a limited period of registration.

A limitation exists in the current rule with a Delhi High Court case filed in 2024 providing the first example of this. In M/S Reflect Sculpt Private Ltd. & Anr. V. Abdus Salam Khan,[¹¹] the organization of designer Gaurav Gupta has brought an action against the defendant who had been copying Gupta’s hand-made designer dress and promoting and selling the copies under the name “GAURAV GUPTA” on social media sites YouTube and Instagram including video instructions about copying the design. On the 3rd of April 2024, Justice Sanjeev Narula granted an ex-parte interim injunction stating that since the garments of the plaintiff were hand-made and were sold less than fifty pieces the provisions of the Section 15(2) bar did not apply in the instant case at least prima facie. The issue did not end at the interim stage as the injunction was made absolute in August 2025. As the court passed the final decree of permanent injunction in pursuance of summary judgment on September 19, 2025, the defendant had not contested the case during proceedings. The final decree was given without any argument on the merits of the case which means the reasoning found in Section 15(2) has not been verified by opposing counsel, unlike in the case of Ritika. Nevertheless, reasoning in both cases illustrates the essence of the rule which states that industrial mass production destroys the copyright in the work while domestic craftsmanship does not.

There is another recent Supreme Court decision that needs to be pointed out, although it is not specifically related to fashion. In Cryogas Equipment Pvt. Ltd. & Anr. V. Inox India Ltd. & Others (April 15, 2025),[12] This case was about a Section 15(2) issue regarding original engineering drawings created for cryogenic LNG storage devices; two judges examined the matter. The Court’s was based on two questions. These were whether the work discussed was an artistic work in true sense or merely a design based on an artistic work which has been practically applied to an object of an article and whether the attached object of the work in question had any primary functional value or was it just with an aesthetic quality. The Court did not determine if Inox’s drawings had any protection but relegated the issue to be looked at considered again using this elucidated manner of the inquiry. The reasoning behind it is based less on engineering drawings as on the laws and therefore could be relevant in future fashion infringement cases, although the laws in question have never been applied directly to fashion products according to known court cases. Therefore, it would be premature to speculate upon the ways in which it and whether it can be extended to something like a mass-market boot silhouette in India.

Beyond the copyright-design overlap, an Indian claimant in a Deckers-Quince-type dispute would also have the Designs Act’s own infringement provision available, but only if the design in question was actually registered; piracy of a registered design carries statutory compensation.[¹³] Separately, passing off remains available regardless of registration status, preserved for unregistered marks and get-up under the Trade Marks Act.[¹⁴] To succeed, a claimant would still need to establish goodwill, misrepresentation and likely damage, the classic passing-off trinity Indian courts have applied since Cadila[¹⁵] and N.R. Dongre.[¹⁶] That is a harder case to make for a functional or industry-generic product than for a genuinely distinctive one, but passing off does not depend on copyright or design registration at all, so Section 15(2) does not foreclose it the way it forecloses a copyright claim.

In conclusion, it seems that in an Indian court, a case similar to the case of Deckers-Quince would involve nearly the same issues as arose in the case in the USA, though these issues would be looked at from the perspective of different doctrine. The main questions in this case would be the following: has the design of the boots been registered or not; if it has not been registered, does it meet the requirements laid down in Section 15(2), meaning that could a product with the design be produced by industrial means in number that exceeds fifty copies, as the criterion of passing the test in question lies precisely in this requirement and is not linked to the issue of mass production in general; and the last issue to be considered is whether the appearance is distinctive enough and likely to cause confusion among the customers so the plaintiff can win his passing-off claim. However, it is important to understand that making predictions regarding the ruling of an Indian court in this hypothetical case goes far beyond what can be supported by the existing case law.

What can be said with confidence is that a claimant in the position of Deckers would likely face substantial challenges on each front and on the facts as presented, a best-selling boot, available in a myriad of styles and sold in hundreds of thousands of units, such as the UGG Classic Ultra Mini, is presumably likely to meet the standard of fifty copies for the purposes of Section 15(2) if it had not been formally registered as a design, thereby destroying any copyright claim; would likely require a new design that is both innovative and properly registered in order to be protected under the Designs Act, which the jury’s finding of invalidity under a different standard suggests may prove challenging if not impossible; and would encounter similar issues of genericness in a passing off claim due to the prevalence of similar shearling boots as described. This is not to suggest what a court would find in any of these cases, but rather to highlight the challenges that a claimant in the position of the UGG trademark owner would encounter in trying to protect such a property under the current copyright registration and protection practices.

VI. Where the Line Actually Sits

Both jurisdictions, through different doctrinal means, converge upon a similar conclusion. The law is not, and should not be, a barrier to companies attempting to create products that are similar to those of their competitors. Resemblance, even when achieved through deliberate reverse-engineering of another’s product, is not in and of itself prohibited by any of the statutes discussed. What the statutes do prohibit is the use of something the law has decided is entitled to protection: a design registered and officially recognized as novel at the time of registration; an artistic work not entirely devalued by its industrial reproduction; a distinctive mark or trade dress which the consumer is likely to associate with a particular producer; or conduct likely to create confusion among consumers about the source of a product.

The Deckers-Quince case is illustrative of both sides of the issue, since it demonstrates how both sides failed to meet the requirements to find a particular product line to be infringing. The case illustrates that different IP rights can produce different outcomes for the same product: the asserted trade dresses were found unprotectable, while the design patent was found to have been infringed but ultimately invalid. The loss of this case does not diminish the ability of fashion houses to use trademark, design, or copyright law to protect their designs, since Deckers retains its other registered protections, and may well bring a stronger case in the future should it choose to do so. A design which incorporates a distinctive but non-functional element can still be protected, so long as the copyright in that design is not devalued by industrial reproduction, or so long as the design is registered and officially recognized as novel.

That leaves duping retailers in a legal grey area, where they are neither entirely within nor entirely without the bounds of the law. Designers who wish to ensure that they are within the bounds of the law must take proactive steps to register their designs, where feasible, or limit the reproduction of their works, where not. They must seek to create wholly new designs which possess some element of non-generic distinctiveness, rather than relying on elements common to their industry. Likewise, duping retailers which wish to avoid infringing can do so by operating within these boundaries as well: by avoiding the imitation of registered designs, copyrighted works, and distinctive elements which consumers are likely to associate with a particular designer or manufacturer, they need not find themselves in conflict with the law, either in the United States or in India.

Frequently Asked Questions

Are fashion dupes illegal in India?

Not automatically. A dupe is not automatically illegal. It may become unlawful where, depending on the facts and applicable law, it infringes a subsisting copyright, a registered design, a registered trademark, or amounts to passing off.

What is the difference between a dupe and a counterfeit?

A counterfeit incorporates a genuine trade mark of the original manufacturer whereas a dupe merely copies certain attributes of the original goods, without using any of its identifiers.

Is a fashion design capable of copyright protection in India?

Indian copyright law may protect artistic works embodied in fashion designs, but Section 15 of the Copyright Act limits that protection where the design is capable of registration under the Designs Act. Under Section 15(2), copyright ceases where such a design is applied to an article and reproduced by an industrial process more than fifty times without registration under the Designs Act.

Can a clothing design be registered in India as a design under the Designs Act, 2000?

Registration is possible if it meets the requirements of originality as per Section 4 of the Designs Act. Thus, the design should be novel or new, not disclosed publicly before the application and have significant difference from the earlier designs, which are known in India.

Is copying of a famous product sufficient for claiming infringement?

No, similarity in design would be sufficient for infringement only if the infringed property right is protected by law and the infringing act constitutes infringement in respect of that right. As in Deckers-Quince case, the plaintiff would have to specifically plead and prove which of the protected property rights (e.g. copyright, design right, etc.) has been infringed by the defendant.

What Should You Actually Protect?

Feature you want to protect	Most relevant legal tool
Brand name or logo	Trademark
Original print, embroidery or fabric artwork	Copyright (subject to Section 15, India)
Overall shape or ornamental appearance of a product	Registered design (India) / design patent (U.S.)
Distinctive overall look or packaging consumers rely on	Trade dress (U.S.) / passing off (India)
A functional mechanism or technical solution	Patent (utility), where the innovation is functional rather than ornamental
A counterfeit product bearing your actual mark	Trademark infringement and, in many jurisdictions, criminal remedies

References

1. Deckers Outdoor Corp. v. Last Brand, Inc., No. 4:23-cv-04850-AMO (N.D. Cal). Docket: CourtListener. https://www.courtlistener.com/docket/67820882/deckers-outdoor-corporation-v-last-brand-inc/

2. ArentFox Schiff. (2025, November 12). UGG-ly result: Court calls Classic Ultra Mini and Tasman trade dress generic, design patent survives.https://www.afslaw.com/perspectives/fashion-counsel/ugg-ly-result-court-calls-classic-ultra-mini-and-tasman-trade-dress

3. The Fashion Law. (2026, June 15). Deckers v. Quince: A timeline of the UGG “dupe” battle.https://www.thefashionlaw.com/deckers-v-quince-a-timeline-of-the-ugg-dupe-battle/

4. Young, V. M. (2026, June 16). Ugg brand owner Deckers Outdoor Corp. loses patent case against Quince. https://wwd.com/footwear-news/shoe-industry-news/ugg-deckers-quince-trial-jury-design-patent-mini-boot-1239011824/

5. Bloomberg Law. (2026, June 15). Deckers loses Ugg patent infringement trial against Quince.https://news.bloomberglaw.com/ip-law/deckers-loses-ugg-boot-patent-infringement-trial-against-quince

6. Saul Ewing LLP. (2026, July 14). The Deckers v. Quince case offers fashion brands guidance amid the growing “dupe” economy. https://www.saul.com/insights/alert/deckers-v-quince-case-offers-fashion-brands-guidance-amid-growing-dupe-economy

7. Knobbe Martens. (2026, June 23). Ben Katzenellenbogen discusses Deckers v. Quince UGG design patent trial with legal and fashion industry media https://www.knobbe.com/updates/ben-katzenellenbogen-discusses-deckers-v-quince-ugg-design-patent-trial-with-legal-and-fashion-industry-media/

8. Copyright Act, 1957 , s. 15 (India).https://www.indiacode.nic.in/bitstream/123456789/15356/1/the_copyright_act,_1957.pdf

9. Ritika Private Ltd. v. Biba Apparels Private Ltd., CS(OS) No. 182/2011, 2016:DHC:2492 (Delhi HC, 23 March 2016). https://delhihighcourt.nic.in/app/case_number_pdf/2016:DHC:2492/VJM23032016S1822011.pdf

10. Microfibres Inc. v. Girdhar & Co. & Anr., RFA(OS) No. 25/2006, (2009) 40 PTC 519 (Delhi HC, 28 May 2009).https://indiankanoon.org/doc/112937069/

11. M/S Reflect Sculpt Private Ltd. & Anr. v. Abdus Salam Khan, CS(COMM) 278/2024 (Del. H.C.). Ex parte interim injunction (Apr. 3, 2024) https://indiankanoon.org/doc/163458652/; final decree of permanent injunction by summary judgment (Sept. 19, 2025).https://indiankanoon.org/doc/131593592/

12. Cryogas Equipment Pvt. Ltd. & Anr. v. Inox India Ltd. & Ors., 2025 INSC 483 (SC, 15 April 2025). https://indiankanoon.org/doc/170672552/

13. Designs Act, 2000 , ss. 2(d), 4, 11, 22 (India). https://www.indiacode.nic.in/bitstream/123456789/1917/1/A2000-16.pdf

14. Trade Marks Act, 1999, s. 27(2) (India). https://www.indiacode.nic.in/bitstream/123456789/1993/1/a199947.pdf

15. Cadila Health Care Ltd. v. Cadila Pharmaceuticals Ltd., (2001) 5 SCC 73 (SC). https://indiankanoon.org/doc/1114158/

16. N.R. Dongre & Ors. v. Whirlpool Corp. & Anr., (1996) 5 SCC 714 (SC). https://indiankanoon.org/doc/1732339/

17. Bharat Glass Tube Ltd. v. Gopal Glass Works Ltd., (2008) 10 SCC 657. (SC). https://api.sci.gov.in/jonew/judis/31381.pdf

18. Gorham Co. v. White, 81 U.S. (14 Wall.) 511 (1871). https://supreme.justia.com/cases/federal/us/81/511/

19. Egyptian Goddess, Inc. v. Swisa, Inc., 543 F.3d 665 (Fed. Cir. 2008) (en banc). https://www.cafc.uscourts.gov/opinions-orders/06-1562.pdf

20. TrafFix Devices, Inc. v. Marketing Displays, Inc., 532 U.S. 23 (2001). https://supreme.justia.com/cases/federal/us/532/23/