Acquired distinctiveness, community recognition and founder-to-maintainer succession under the UDRP

Can an open-source software project establish unregistered trademark rights without conventional sales, advertising expenditure or a traditional commercial enterprise? And where a project was founded by one developer but subsequently maintained by another, who is entitled to assert those rights?

Both questions arose in Eric Voskuil v. Timur Gavrylenko, WIPO Case No. D2026-3527, decided on October 12, 2026.

The dispute concerned <libbitcoin.org>, a domain name historically associated with the LIBBITCOIN open-source software project. Following the expiration of its registration in June 2026, the respondent acquired the domain name and used it to host a copy of the project’s website.

The complainant, Eric Voskuil, relied upon unregistered trademark rights arising from fifteen years of documented development activity, public distribution, independent recognition and continuity of project stewardship.

The Panel found that LIBBITCOIN had acquired distinctiveness and that Voskuil had established rights sufficient for standing under the UDRP. It ordered the domain name transferred.

The decision is particularly instructive when contrasted with cases where UDRP claims based on unregistered trademark rights failed for lack of sufficient evidence.

Establishing Trademark Rights in an Open-Source Project

Paragraph 4(a)(i) of the Uniform Domain Name Dispute Resolution Policy requires a complainant to establish rights in a trademark or service mark to which the disputed domain name is identical or confusingly similar.

Registration is not indispensable.

Under section 1.3 of the WIPO Overview 3.1, unregistered trademark rights may be established where the claimed designation has acquired distinctiveness—that is, where the relevant public recognises it as identifying the source of particular goods or services.

Relevant evidence may include the duration and nature of use, sales, advertising, public recognition and consumer surveys. These factors are not a rigid checklist.

The critical distinction is between evidence that a designation has been used, announced or promoted and evidence that it has actually acquired source-identifying significance among the relevant public. The former may contribute to the latter but does not necessarily establish it.

For open-source projects, conventional commercial indicators may be less informative. Software may be distributed freely, developed collaboratively and adopted within a specialised technical community without substantial sales or advertising expenditure.

The absence of those indicators does not dispense with the requirement to establish acquired distinctiveness. Rather, the evidence must demonstrate that the relevant public, including, where appropriate, a specialised developer community, recognises the designation as identifying a particular source.

LIBBITCOIN is an open-source C++ Bitcoin software toolkit founded by Amir Taaki and publicly announced under that name in July 2011.

The complainant submitted evidence of continuous development activity, including early software commits, subsequent development records, public announcements, software repositories and independent references within the Bitcoin community.

The Panel considered the cumulative significance of the project’s documented history, public distribution, community engagement and independent media recognition.

A repository may establish that software exists under a particular name. A development history may demonstrate sustained activity. Neither necessarily establishes trademark rights.

The additional evidence of independent community and media recognition supported the Panel’s conclusion that LIBBITCOIN had acquired distinctiveness as a source identifier among the relevant public. Its significance lay not merely in demonstrating that the project was known, but in supporting the finding that the LIBBITCOIN designation had come to identify the source of the software.

The Panel also regarded the respondent’s reproduction of the project’s website as corroborative evidence of acquired distinctiveness, although not independently determinative.

On the totality of the record, the Panel found that LIBBITCOIN had become a distinctive identifier of the project sufficient to establish unregistered trademark rights under the Policy.

Founder-to-Maintainer Succession: Who Can Assert the Rights?

The most distinctive aspect of LIBBITCOIN concerns the relationship between the project’s founder, Amir Taaki, and its subsequent maintainer, the complainant Eric Voskuil.

Establishing that LIBBITCOIN had acquired trademark significance did not, without more, establish that Voskuil was entitled to assert the associated rights.

This distinction is particularly important in open-source development, where projects may involve numerous contributors, changes in leadership and informal governance arrangements.

The Panel expressly identified four matters supporting Voskuil’s entitlement.

• First, authorship and project association. Voskuil was credited as an author alongside Taaki on the LIBBITCOIN website, connecting him to the project’s publicly presented identity.
• Second, control of project-associated domain names. Voskuil controlled <libbitcoin.info>, <libbitcoin.net> and <libbitcoininstitute.org>. Although domain-name ownership does not itself establish trademark ownership, such control supported his continuing association with the project.
• Third, an agreement concerning the disputed domain name. The record contained a documented agreement between Taaki and Voskuil that <libbitcoin.org> could be transferred to Voskuil’s registrar account. This supported the history of acknowledged stewardship of an important project asset.
• Fourth, the founder’s express acknowledgement and consent. Taaki confirmed that he had ceased involvement with the project in 2015, that Voskuil had led and maintained it since then, and that Taaki asserted no claim to the LIBBITCOIN mark. He also consented to Voskuil asserting those rights in the UDRP proceedings.

The fourth consideration is particularly significant. The Panel was not required to infer Voskuil’s entitlement solely from technical contributions or maintenance responsibilities. It had evidence acknowledging his stewardship and the founder’s express position concerning the claimed rights.

Nevertheless, the limits of the finding must be recognised.

The Panel did not expressly find that Taaki had formally assigned trademark rights or transferred the associated goodwill to Voskuil. The documented agreement concerned a domain-name transfer, not a trademark assignment.

Nor could the founder’s consent independently create trademark rights. Their existence depended upon the separate evidence that LIBBITCOIN had acquired distinctiveness.

The Panel’s conclusion concerned Voskuil’s rights for purposes of UDRP standing, not a comprehensive determination of trademark ownership under national law.

The decision therefore illustrates how entitlement may be substantiated through documented authorship, continuity of stewardship, control of project-associated assets and acknowledgement by the original founder. It does not establish that a project’s current maintainer automatically succeeds to its trademark rights.

The Contrasting Authorities: When the Evidence Is Insufficient

The significance of LIBBITCOIN becomes clearer when compared with Can Saygun v. Gene M Bleich, seo, WIPO Case No. D2025-5396 (NETBAHIS).

The complainant asserted registered and unregistered trademark rights based upon a pending United Kingdom trademark application, an alleged assignment and claimed longstanding commercial use.

However, the application remained pending in another entity’s name, and the complainant produced no assignment agreement or adequate evidence of acquired distinctiveness.

Despite two procedural orders inviting further substantiation, the deficiencies remained.

Significantly, the respondent’s websites had used logos highly similar or identical to those appearing on the complainant’s website. Nevertheless, the Panel found that the evidence did not establish the claimed trademark rights and denied the complaint under the first element.

The contrast with LIBBITCOIN is striking.

Both proceedings were undefended. Both involved procedural orders. Both contained evidence suggesting respondent imitation.

Yet the outcomes differed because of the evidentiary records.

In LIBBITCOIN, the copycat website supplemented extensive documentation of project history, independent recognition and acknowledged stewardship.

In NETBAHIS, apparent imitation did not cure the failure to establish the underlying rights and entitlement.

A further illustration appears in Dr. Michael W. Piepkorn v. Siddharth Jha, Pier 67 Capital Partners LP, WIPO Case No. D2025-4640 (MICHAEL PIEPKORN MD).

There, evidence of professional reputation, textbook authorship and certain commercial activity did not establish that the complainant’s name functioned as a trademark rather than identifying him as an author or medical professional.

The distinction is fundamental: recognition of a person or project is not necessarily recognition of a designation as a trademark. The evidence must establish that the designation has acquired source-identifying significance among the relevant public.

Targeting, Bad Faith and the Limits of the Decision

The respondent acquired <libbitcoin.org> in July 2026, approximately fifteen years after the project’s commencement.

The domain name then resolved to a copy of the project’s website, including material specifically identifying Voskuil as an author.

The Panel considered it implausible that the respondent was unaware of the complainant and the mark when registering the domain name. It found bad-faith registration and use, including intentional attraction of Internet users for commercial gain through confusion concerning source, sponsorship, affiliation or endorsement.

The original registration of the domain name in 2011 did not insulate the respondent’s subsequent acquisition from scrutiny.

Nevertheless, the finding of trademark standing must remain distinct from the finding of bad faith. The former concerns the existence of rights; the latter concerns the respondent’s conduct and intentions.

A further qualification concerns the procedural record.

The respondent filed no Response and did not answer the Panel’s procedural order. The Panel received additional submissions from the complainant, but the published decision does not identify precisely which documents were supplied in response to the order.

The evidence concerning stewardship and entitlement was therefore not tested against substantive competing submissions.

LIBBITCOIN should accordingly be understood as illustrating how documentary evidence may establish acquired distinctiveness and substantiate a complainant’s entitlement to assert trademark rights under the UDRP, rather than definitively resolving contested questions of trademark succession in decentralised software projects.

Conclusion

LIBBITCOIN demonstrates that an open-source software project may establish unregistered trademark rights through evidence appropriate to the manner in which its reputation has developed.

Sustained development activity, public distribution, community engagement and independent recognition may collectively establish acquired distinctiveness, even without conventional commercial indicators. But the evidence must demonstrate that the designation has actually acquired source-identifying significance among the relevant public.

The decision’s more distinctive contribution concerns the separate question of entitlement to the rights being asserted.

Where a project has passed from its founder to a subsequent maintainer, the complainant must establish a sufficient evidentiary basis for asserting the associated trademark rights.

The comparison with NETBAHIS and MICHAEL PIEPKORN MD reinforces the importance of substantiating both acquired distinctiveness and entitlement, rather than relying upon assertions of reputation, historical activity or respondent targeting.

The governing distinction is between proving that a project exists, proving that its name has acquired trademark significance, and proving that the complainant is entitled to assert the resulting rights.

LIBBITCOIN illustrates why all three questions matter—and why each requires evidence.