The “Mario” Mistake: Crowded Field Lessons In TM Refusals
For many entrepreneurs, naming a brand after a founder feels like the safest, most authentic choice. It’s personal. It’s memorable. It signals accountability. But in trademark law, a common first name can be a surprisingly risky foundation—especially in industries like apparel, beauty, food, and retail, where personal-name branding is everywhere.
A recent 2026 precedential decision from the Trademark Trial and Appeal Board (TTAB) shows just howunforgiving a “crowded field” argument can be when you’re trying to overcome a Section 2(d) likelihood of confusion refusal. In re Mario’s LLC, the trademark applicant sought to register MARIO’S for clothing, only to be blocked by an older trademark registration for MARIO’S 3.10 for retail apparel store services. The applicant tried to argue, in essence, “Mario is a common name—consumers can tell these apart.” The Board was not persuaded—and the opinion is a useful roadmap for what does (and does not) work when you argue that the marketplace is crowded.
What happened in In re Mario’s LLC
The trademark applicant applied to register MARIO’S (standard characters) for a broad range of clothing items in International Class 25—everything from shirts and hats to shoes, socks, belts, and jackets. The USPTO refused trademark registration under Section 2(d) based on a cited registration for MARIO’S 3.10 (standard characters) for “Retail apparel stores” in International Class 35. After a final trademark refusal, the applicant appealed, and the TTAB affirmed the refusal (while noting the trademark application could proceed for separate Class 18 goods not at issue in the appeal).
For business owners, the case matters for two reasons. First, it highlights a common misconception: “We sell products; they run a store—so we’re different.” Second, it illustrates the high evidentiary bar for proving that a term is so diluted by third-party use that consumers can reliably distinguish between lookalike trademarks based on small differences.
The Section 2(d) Likelihood of Confusion Framework
Section 2(d), likelihood of confusion, prevents registration of a trademark that is likely to cause consumer confusion with an existing trademark. The TTAB evaluates confusion in the marketplace using the DuPont factors, but in most ex parte trademark application cases, two factors dominate: (1) how similar the trademarks are and (2) how related the goods/services are.
In other words, the question is not “Are these businesses actually confusing people today?” It’s “Would ordinary consumers be likely to assume the same source, sponsorship, or affiliation if these trademarks appeared in the marketplace for the identified goods and services?”
Why “Clothing” and “Retail Apparel Stores” Collide More Often than People Expect
A lot of founders assume that trademark “classes” function like separate lanes: Class 25 is for clothing, Class 35 is for retail store services, and the two shouldn’t conflict. But the TTAB has long treated retail services and the goods sold through those services as naturally related. In Mario’s, the Board found the relationship essentially obvious: the registrant’s services involve the retail sale of apparel, and the applicant’s goods are apparel. The Board held the goods and services were “related on their face.”
This point is bigger than apparel. If you’re launching a brand of packaged coffee, a similarly named café chain can be a real obstacle. If you sell skincare, a similarly named spa or boutique can matter. The trademark system isn’t only protecting product-to-product comparisons; it’s protecting consumers from confusion across the channels where products are sold and promoted.
The “Lead Term” Problem: Why MARIO’S Dominated MARIO’S 3.10
The applicant leaned hard on the idea that 3.10 makes the registered mark meaningfully different. The TTAB disagreed and emphasized a concept founders run into constantly: the dominant first portion (sometimes called the “lead term”) often carries the most source-identifying weight.
Both trademarks begin with MARIO’S, and the applicant’s trademark is fully contained within the registered trademark. The Board concluded the trademarks are “very similar” in sound and appearance because consumers tend to focus on and remember the first word or phrase.
Even more important, the Board explained why a number can increase confusion instead of reducing it. It found consumers could perceive “3.10” as suggesting an iteration, version, or line extension—meaning buyers might think MARIO’S is a product line from the MARIO’S 3.10 retail brand.
This is a practical branding point: adding a number, a short suffix, or a minor modifier often reads like “sub-branding,” not a clean separation.
The Heart of the Case: Why the “Crowded Field” Defense Didn’t Land
The trademark applicant’s main strategy was to argue that MARIO is weak for clothing because so many third parties use it—so consumers are “educated” to notice small differences. The Board addressed this under the DuPont factor that considers “the number and nature of similar trademarks in use on similar goods,” which goes to the strength (or weakness) of the cited trademark.
A key takeaway from the opinion is that “crowded field” is not just a counting exercise. The Board’s analysis effectively asks two questions:
The trademark applicant submitted numerous registrations containing MARIO, but the Board found many weren’t actually probative because they created different commercial impressions. For example, trademarks pairing MARIO with a surname (e.g., MARIO VALENTINO, MARIO ROSSI, MARIO HERNANDEZ and similar) were treated as evoking a fashion designer identity—commercially distinct from MARIO’S standing alone.
The Board also discounted trademarks tied to unrelated commercial impressions, such as Nintendo-associated “Super Mario” and “MarioKart,” and cigar-store-related “Mario’s Bohemian Cigar Store.”
After filtering out the less relevant examples, the Board found only a small handful meaningfully supported the applicant’s position—most notably MMMM MARIO’S, plus CHEERFUL MARIO and MARIO MILLIONS as “somewhat probative.” But the Board said these were too few to show the MARIO’S portion of the cited mark was weak enough to deserve only limited protection.
This is where many applicants misjudge what “crowded” means in TTAB practice. You need volume, yes—but you also need proximity: the third-party trademarks must be close in structure and used (or registered) for closely related goods/services, such that consumers routinely encounter similar-looking marks in the same shopping context.
Registrations vs. Real-World Use: Why Evidence Quality Matters
The opinion reinforces another hard truth: third-party registrations can help show conceptual weakness, but they don’t automatically prove what consumers actually see in the marketplace. The Board noted it could consider evidence of third-party use submitted for some registrations for both conceptual and commercial strength.
For entrepreneurs, that’s a strategic lesson. If you’re facing a 2(d) likelihood of confusion refusal and want to argue dilution or crowding, the most persuasive record usually includes marketplace proof: brand websites, store listings, product pages, social media presence, press mentions, and other evidence showing consumers are exposed to multiple similar trademarks in the same space. A stack of registrations—especially when many belong to the same owner or point to different commercial impressions—often won’t carry the day.
“But Someone Else Registered MARIO Before!” Why Coexistence Arguments Often Fail
The trademark applicant also pointed to a prior MARIO registration for clothing that once coexisted with the cited registration. The Board gave that little weight because the referenced registration was cancelled, and prior coexistence on the register doesn’t prove coexistence without confusion in the marketplace.
This comes up a lot in practice: founders find older, similar registrations and assume that means the USPTO must approve their mark too. But trademark examination is not a strict “treat like cases alike” system. Status changes, record differences, and evidentiary differences matter, and the TTAB repeatedly emphasizes that each case turns on its own facts.
The “Sophisticated Consumers” Trap
The applicant argued clothing buyers are sophisticated because fashion is “fashionable,” and that consumers would notice differences. The Board rejected the argument because there was no evidence in the record supporting heightened purchaser care; attorney argument alone isn’t enough. With no evidence, the Board treated the purchasing conditions factor as neutral and evaluated likelihood of confusion from the perspective of ordinary consumers (including the least sophisticated).
If your brand plan relies on “We’re high-end, so our customers pay attention,” that can be a valid argument in the right case—but you should be prepared to back it up with concrete proof (pricing, purchasing process, specialized channels, or other evidence showing careful purchasing).
Practical lessons for business owners naming brands in a crowded market
The Mario’s opinion isn’t a warning against using personal names. It’s a warning against assuming personal names are automatically protectable—or that “everyone uses it” is an easy defense.
If you’re choosing a trademark now, the best prevention strategy is to treat naming like risk management. Search for pending trademark applications and existing trademark registrations beyond the obvious competitors and beyond your product class. If you sell goods, search for retail and online store services that sell those goods. If you plan to expand, search adjacent categories you may realistically move into. The Board’s reasoning shows that channels of trade and natural commercial relationships can connect your goods to someone else’s services even when the “classes” differ.
If you’re already facing a 2(d) likelihood of confusion refusal and want to make a crowded field argument, build the record as if you’re teaching the Examining Attorney (and the Board) what consumers actually encounter. Focus on trademarks that are close in structure to yours, used for closely related goods/services, encountered in overlapping shopping contexts. Show breadth (many sources) and depth (real marketplace presence). Avoid relying on trademarks that merely share a first name but convey a different commercial impression—like designer-name formats, famous entertainment properties, or unrelated industries—because the Board may view those differences as too substantial to be “minute distinctions.”
Finally, consider branding adjustments that genuinely change commercial impression, not just minor suffixes. The TTAB’s treatment of “3.10” underscores that small modifiers can read like a product line rather than a different source. If your goal is registrability and long-term enforceability, a more distinctive trademark—whether fanciful, arbitrary, or a unique composite—often costs less in the long run than fighting uphill over a common name.
Lessons Learned From Mario’s 2026 Precedential TTAB Decision
In re Mario’s LLC is a clean, precedential reminder that “crowded field” isn’t a magic phrase—it’s an evidence-driven argument. And when the shared portion of two trademarks sits at the front, and the goods and services naturally overlap in the way consumers shop, the Board is likely to side with preventing confusion over rewarding a founder’s preferred name.
If you’re building a new brand—or trying to save one after a refusal—this case is a strong prompt to treat clearance searches, naming, and evidence strategy as early-stage business essentials, not afterthoughts.