You build a product page that says "compatible with Salesforce." Three weeks later, a cease-and-desist letter arrives claiming trademark infringement. Your first instinct is to invoke fair use as a trademark infringement defense, but which fair use? There are two distinct doctrines with different legal tests and different risk profiles, and conflating them is one of the most common mistakes companies make when referencing another brand's trademark.
Trademark fair use is two separate legal doctrines that happen to share a name. Classic (descriptive) fair use protects your right to use a trademarked word in its ordinary dictionary sense. Nominative fair use protects your right to refer to the trademark holder's actual product by name. The tests are different, the case law is different, and the outcomes can diverge sharply depending on which one applies.
This is educational, not legal advice. Consult a trademark attorney for guidance specific to your situation.
Two Types of Trademark Fair Use
Most articles on trademark fair use treat it as one thing. That is wrong, and the error leads people to apply the wrong test to their situation. A developer writing "compatible with Salesforce" on an integration page is doing something fundamentally different from a restaurant calling its Friday special a "fish fry," even though both might invoke fair use as a defense.
Classic fair use (also called descriptive fair use) is statutory. It is codified in Section 33(b)(4) of the Lanham Act, the federal statute governing trademarks in the United States (15 U.S.C. Section 1115(b)(4)). It permits you to use a term that happens to be trademarked in its ordinary descriptive sense, provided you do so in good faith and not as a trademark. The word "sharp" is a registered trademark for electronics. But a knife company can still describe its blades as "sharp" because it is using the word descriptively, not as a brand identifier.
Nominative fair use is judge-made law, not statutory. The Ninth Circuit created it in 1992 to address situations where you need to refer to a trademarked product by name. If you are building a Slack alternative, there is no way to say that without using the word "Slack." The doctrine recognizes this practical reality and provides a framework for when such references are permissible.
The distinction matters because each doctrine has its own legal test. Apply the wrong test and you will either overestimate your protection (dangerous) or avoid a reference you are legally entitled to make (costly). A company deciding whether to put "works with Stripe" on its homepage needs nominative fair use analysis, not classic fair use. Getting this right at the outset shapes the entire legal calculus.
Classic Fair Use: Using Words as Words
The statutory text at 15 U.S.C. Section 1115(b)(4) establishes three elements for a classic fair use defense. The use must be (1) a term used descriptively, not as a trademark, (2) used fairly and in good faith, and (3) used only to describe the defendant's goods or services. All three must be satisfied.
"Fish Fry" is a registered trademark for a particular brand of seafood batter. But a restaurant advertising its Friday fish fry is using the phrase descriptively to describe a type of meal. "Honey" is a registered trademark in several categories. A cereal maker listing honey as an ingredient on its packaging is describing the product's contents, not trading on the "Honey" brand.
The Supreme Court clarified an important procedural point in KP Permanent Make-Up, Inc. v. Lasting Impression I, Inc. (2004). Before this decision, some circuits required the defendant to prove that its fair use did not cause a likelihood of confusion, effectively making the defense nearly impossible to win. The Court unanimously held that the defendant does not bear the burden of disproving likelihood of confusion in a classic fair use defense. Some degree of consumer confusion is compatible with fair use.
But classic fair use has clear failure modes. The defense collapses when you use a descriptive term in a trademark-like way. If you put "SHARP" in large, stylized lettering on your electronics packaging in a way that suggests it is your brand name, the descriptive defense fails. The question is whether the term functions as a source identifier. Size, placement, styling, and context all factor into this analysis.
Good faith is the element that receives the least attention but can be decisive. If you adopted a descriptive term after becoming aware of the trademark holder's mark, and your use is designed to create an association with that mark, courts will be skeptical of your claim to good faith. Good faith does not mean merely that you did not intend to infringe. It means your use was genuinely descriptive, not an attempt to trade on someone else's brand equity.
Classic fair use is not an exception to trademark law. It is built into the structure of the Lanham Act, the same statute that creates the distinction between intent-to-use and use-in-commerce filings. The principle is that trademark rights cannot monopolize the ordinary descriptive use of language.
Nominative Fair Use: Naming the Brand
The foundational case is New Kids on the Block v. News America Publishing Co. (1992), decided by the Ninth Circuit. Two newspapers ran polls asking readers to vote for their favorite member of the band New Kids on the Block. The band sued for trademark infringement. The court recognized that the newspapers could not conduct the polls without using the band's name and established a three-part test for nominative fair use.
The test requires that (1) the product or service in question is not readily identifiable without using the trademark, (2) only so much of the mark is used as is reasonably necessary to identify the product or service, and (3) the user does nothing that would suggest sponsorship or endorsement by the trademark holder.
This doctrine is why comparative advertising works. You can say "faster than Salesforce" or "a Slack alternative" or "works with Stripe" because there is no way to make these claims without naming the other product. The first prong is almost always satisfied in these cases. There is usually no other way to refer to the trademark holder's product.
The second prong is where companies get into trouble. Using the trademarked name in text is almost always fine. Using the company's logo, trade dress, or color scheme is a different question. If you put the Salesforce cloud logo on your product page next to "compatible with Salesforce," you are using more of the mark than reasonably necessary to identify the product. The text alone would suffice. Logos carry stronger source-identifying weight than word marks, and their use makes it harder to satisfy the "no suggestion of endorsement" requirement under the third prong.
The third prong, no suggestion of sponsorship or endorsement, is the most fact-intensive. Saying "compatible with Salesforce" is different from saying "recommended by Salesforce" or "official Salesforce partner." The first is a factual claim about interoperability. The second and third imply a relationship that may not exist. Layout and design choices matter here too. If you place a competitor's name in a way that suggests affiliation (in a partner badge, in a list of "trusted by" logos), you risk failing this element.
There is a significant complication: the federal circuits do not agree on how nominative fair use works. The Ninth Circuit treats it as a complete replacement for the standard likelihood-of-confusion analysis. If the defendant satisfies all three prongs, the inquiry ends.
The Second Circuit, in International Information Systems Security Certification Consortium, Inc. v. Security University, Inc. (2016), rejected this approach. It held that nominative fair use should be considered as part of the broader likelihood-of-confusion analysis, not as a separate test that displaces it. Under this framework, the nominative fair use factors are folded into the standard multifactor confusion test, making the defense harder to win in practice.
This circuit split means that the strength of your nominative fair use defense depends partly on where you are sued. A reference that is clearly protected in the Ninth Circuit (covering California and much of the West) might be more vulnerable in the Second Circuit (covering New York). Companies with national exposure should evaluate their use under both frameworks and make decisions based on the more restrictive standard.
Fair Use Outside the US
The principle that trademark rights have limits is not unique to the United States, but the specific frameworks vary by jurisdiction. Companies operating across borders need to understand where their use is protected and where it might not be.
The EU Trade Mark Regulation (2017/1001) addresses trademark limitations in Article 14. It identifies three categories of permitted use: (1) use of a person's own name or address, (2) use of descriptive indications (characteristics, quality, geographical origin), and (3) use of a trademark to indicate the intended purpose of a product or service, particularly for accessories or spare parts. The third category is the EU's closest equivalent to nominative fair use, though it is narrower in scope and framed differently. All three are subject to a general requirement of use "in accordance with honest practices in industrial or commercial matters."
The EU framework is narrower than the US approach in some respects and broader in others. It is narrower because it does not explicitly create a general right to use a trademark for comparative advertising purposes under Article 14 itself (that right comes from the separate Comparative Advertising Directive). It is broader because the "honest practices" standard is more flexible than the rigid prong-based tests used by US circuits. For companies registering trademarks in the EU, understanding these limitations from the outset is important for enforcement strategy.
The UK, post-Brexit, retains a substantially similar framework under Section 11 of the Trade Marks Act 1994. The permitted uses largely mirror the EU provisions: own-name use, descriptive use, and intended-purpose use, all subject to the honest practices requirement. UK courts continue to reference pre-Brexit CJEU case law as persuasive (though no longer binding) authority on these provisions.
Most trademark systems recognize some form of fair use or permitted use, but the scope varies substantially. The differences in how jurisdictions handle trademark protection extend to how they handle its limits. A use that is clearly defensible in the US under nominative fair use might not have an equivalent defense in a jurisdiction that lacks a comparable doctrine. Companies operating internationally should evaluate fair use on a jurisdiction-by-jurisdiction basis rather than assuming that a US-based analysis translates globally.
Practical Checklist: Is Your Use Defensible?
Any trademark fair use defense starts with correctly classifying your use. If you are using a word that happens to be trademarked in its ordinary descriptive sense (describing your own product's characteristics), you are in classic fair use territory. If you are using the trademark to refer to the trademark holder's actual product (comparison, compatibility, commentary), you are in nominative fair use territory. This classification determines which test applies.
For classic fair use, verify three things. First, are you using the term descriptively, or is it functioning as a brand identifier in your context? Consider how it appears visually. Large, stylized, and prominent placement suggests trademark use. Small, inline text describing a feature suggests descriptive use. Second, is your use in good faith? If you adopted the term knowing about the trademark and hoping to create an association, your claim weakens substantially. Third, are you using the term only to describe your own goods or services?
For nominative fair use, apply the three-prong test. Can you identify the product or service you are referencing without using the trademark? (Usually not, which is why you need the doctrine.) Are you using only as much of the mark as necessary? (Text is usually fine. Logos, trade dress, and color schemes are usually too much.) Does your use suggest sponsorship, endorsement, or affiliation? (If it does, even implicitly, you have a problem.)
Red flags that undermine any fair use claim:
- Using a competitor's logo when the word mark alone would suffice
- Placing another brand's name in a "partners" or "trusted by" section without an actual partnership
- Adopting a descriptive term as a prominent brand element after learning it is trademarked
- Styling or formatting another brand's name to look like your own branding
- Making claims about a relationship (official, certified, endorsed) that does not exist
When to get a trademark attorney involved. If your use is prominent (homepage, product name, advertising campaign), if you have received a cease-and-desist, if you operate in multiple jurisdictions, or if the trademark holder is a large company with active enforcement. Fair use is a defense, not a license. The analysis may seem straightforward in the abstract, but courts are fact-intensive in their application. The difference between "probably fine" and "legally protected" is the difference between a blog post and a legal opinion.
"Probably fine" is a risk assessment. Most companies that say "compatible with X" on a product page never hear from the trademark holder. But "probably fine" is not a legal defense if you do hear from them. If the reference is important to your business, invest in the legal analysis to confirm it is defensible, not just tolerable.
Two Doctrines, Not One
Trademark fair use is two doctrines, not one. Classic fair use protects descriptive language. Nominative fair use protects references to the trademark holder's product. They apply different tests, the circuits do not fully agree on the nominative framework, and international jurisdictions have their own variations. Getting the classification right is the first step in any fair use analysis.
If you are building a product that references other brands in comparison pages, compatibility claims, or marketplace listings, understanding these boundaries is not optional. Signa's trademark search API can help you identify which names are registered and in which jurisdictions, giving you the factual foundation for a proper fair use analysis.
This article is educational and does not constitute legal advice. Consult a trademark attorney for legal guidance specific to your situation.