The Federal Circuit’s decision in In re Brunetti, No. 23-1539 (Fed. Cir. Aug. 26, 2025), sits at the uneasy intersection of trademark doctrine, administrative law, and cultural ubiquity. At issue was whether the word “FUCK,” sought to be registered in standard characters for a range of consumer goods and retail services, fails to function as a trademark because consumers would not perceive it as identifying a single source. The court largely rejected Erik Brunetti’s constitutional arguments but nonetheless vacated and remanded the Trademark Trial and Appeal Board’s refusal, faulting the Board for failing to articulate a clear, reviewable standard under the Administrative Procedure Act.
The result is not a holding that FUCK must be registered. Instead, the court sent the case back with instructions that amount to a polite but pointed reminder: agencies cannot decide cases based on vibes. They must explain themselves.
Background and the Board’s Decision
Brunetti filed four intent-to-use applications in 2019 seeking registration of the word FUCK for goods including sunglasses, jewelry, bags, and related retail services. After the Supreme Court’s decision in Iancu v. Brunetti eliminated the Lanham Act’s bar on “immoral or scandalous” marks, the examining attorney shifted gears and refused the applications on a different ground: failure to function as a trademark under Sections 1, 2, 3, and 45 of the Lanham Act.
The examining attorney characterized FUCK as “widely-used commonplace wording,” supported by extensive evidence of third-party use on similar consumer goods. The Board affirmed in a precedential decision, emphasizing that the relevant public is accustomed to seeing the word used by many different sources to convey a wide range of emotions and sentiments. Because of that ubiquity, the Board concluded, consumers would not perceive the word as a source identifier for Brunetti’s goods or services.
On appeal, Brunetti advanced several arguments. He contended that the refusal amounted to viewpoint discrimination, retaliation for his prior Supreme Court victory, and an impermissible resurrection of the “immoral or scandalous” bar under a different label. He also argued that the Board had effectively created a new per se rule barring registration of “widely-used” words.
The Federal Circuit rejected most of those arguments. The constitutional claims failed, the court explained, because failure-to-function analysis is viewpoint-neutral and focuses on consumer perception, not message approval or disapproval. Nor did Iancu v. Brunetti dictate the outcome, because that case involved a different statutory provision and a different mark (FUCT rather than FUCK).
So far, so ordinary. The surprise came next.
Failure to Function and the Limits of Commonality
Trademark law has always required that a mark identify source. As the court reiterated, distinctiveness is the classic pathway, whether inherent or acquired. But distinctiveness and failure to function are not coextensive. Even a designation that might be arbitrary or suggestive in the abstract can be refused registration if, in practice, consumers do not perceive it as indicating a single source.
The Board leaned heavily on this principle, characterizing FUCK as an “all-purpose word” with a multitude of meanings and extraordinary prevalence in the marketplace. The Federal Circuit did not dispute that factual premise. Indeed, the court accepted that the record supported the conclusion that the word is used ubiquitously across goods similar to those in Brunetti’s applications.
What troubled the court was not the conclusion, but the path taken to reach it.
The Board repeatedly insisted that “commonality is not the test,” while at the same time relying on commonality to deny registration. It dismissed Brunetti’s reliance on other registered marks, including registrations for LOVE and even third-party registrations for FUCK itself, as irrelevant because they lacked “contextual information.” Yet the Board never explained what context would matter, how it would be evaluated, or how an applicant could ever satisfy the standard.
As the majority put it, the Board appeared to be applying an “I know it when I see it” approach to failure-to-function refusals. That may be tempting when dealing with a word as culturally saturated as FUCK, but it is not compatible with reasoned decision-making under the APA.
Administrative Law, Not Cultural Commentary
A central theme of the opinion is that trademark examination does not occur in a vacuum. The PTO processes applications through hundreds of examining attorneys, and inconsistency at the examination level is inevitable. Prior registrations do not bind the agency, and erroneous approvals do not compel repetition of the error.
But inconsistency does not absolve the Board of its obligation to articulate a coherent standard, particularly in a precedential decision. The court invoked Booking.com to underscore that the PTO must consider its own past practice when developing comprehensive rules. And it emphasized long-standing administrative law principles requiring agencies to explain the reasoning behind their decisions with enough clarity to permit judicial review.
Here, the Board failed that test. It did not explain when an “all-purpose word” crosses the line from registrable to inherently incapable of functioning as a mark. It did not explain what evidence could rebut a prima facie case of failure to function. And it did not reconcile, even at a high level, why some ubiquitous words can serve as marks while others cannot.
The result, according to the court, is doctrinal drift. Without articulated standards, failure-to-function refusals risk becoming unpredictable and unreviewable, particularly as the doctrine expands beyond classic informational slogans into broader categories of language.
The Dissent: Sometimes the Answer Is Obvious
Judge Lourie dissented, and his opinion captured the intuitive appeal of the Board’s original decision. In his view, substantial evidence supported the conclusion that consumers cannot associate the f-word with a single source because of its sheer ubiquity and semantic elasticity. He distinguished words like LOVE and phrases like “F— cancer” as having more limited, focused meanings, capable of serving as source identifiers despite their frequency of use.
For Judge Lourie, the majority’s concern with analytical precision missed the forest for the trees. The record was sufficient. The conclusion was clear. Remand would only prolong a case that, in his view, had already consumed nearly a decade.
That tension between doctrinal rigor and practical intuition is the beating heart of this case.
Why This Case Matters Beyond Four Letters
For practitioners, In re Brunetti is less about profanity and more about process. The Federal Circuit did not bless the registration of FUCK. Instead, it insisted that if the PTO is going to deny registration based on failure to function, it must explain how and why, in a way that can be applied consistently and reviewed meaningfully.
This matters because failure-to-function refusals are on the rise. The doctrine increasingly operates as a catch-all for designations that make examiners uncomfortable but do not fit neatly into traditional distinctiveness categories. Without clear standards, applicants are left guessing what evidence will matter and how to structure their records.
As Charles Gideon Korrell observes, the decision reflects a broader trend in Federal Circuit jurisprudence: heightened sensitivity to administrative law constraints even in areas traditionally viewed as examiner-driven and discretionary. That perspective is particularly relevant for trademark applicants pushing boundaries with minimalist branding, slogans, or culturally loaded language.
The opinion also signals that the PTO cannot sidestep its own precedents by invoking case-by-case discretion without explanation. While prior registrations do not control, they do form part of the backdrop against which reasoned decision-making is assessed.
Charles Gideon Korrell notes that this case may ultimately force the Board to articulate a clearer framework for evaluating when widespread third-party use negates source significance, and when it merely reflects a crowded but registrable field. That guidance, if it emerges on remand, could shape trademark prosecution strategy well beyond this case.
Looking Ahead
On remand, the Board faces an unenviable task. It must either articulate a principled standard that explains why FUCK cannot function as a mark for these goods, or reconsider its refusal in light of a clarified framework. Either way, the decision will likely become a reference point for future failure-to-function disputes involving ubiquitous language.
For now, In re Brunetti stands as a reminder that trademark law, for all its cultural entanglements, is still administrative law at its core. Even when the answer feels obvious, the agency must show its work.
Charles Gideon Korrell believes that insistence on articulated standards, rather than intuitive judgments, is what ultimately keeps trademark law predictable enough to function in a crowded and expressive marketplace. Whether the Board can deliver that clarity on remand remains to be seen.