Since its inception in 2001, the online encyclopedia Wikipedia1 has grown to be the largest encyclopedia ever assembled. Currently ranked among the world’s top ten most-visited websites, Wikipedia boasts 6.8 million registered users and 8.29 million articles worldwide.2

Wikipedia has even made its way into numerous U.S. judicial opinions.3 More than 100 judicial rulings have cited Wikipedia, including 13 circuit courts of appeal. Use of Wikipedia by courts, however, has not been without controversy.

Due to concerns about the ability of anonymous users to edit Wikipedia entries, some courts have questioned Wikipedia’s reliability and subsequent admissibility. Two recent trademark cases, though recognizing Wikipedia’s shortcomings, have distinguished these earlier cases, and considered Wikipedia entries where the non-offering party has had an opportunity to rebut the evidence.


In two early non-trademark cases concerning Wikipedia, courts questioned its reliability because anonymous users can edit its articles.4 Concerned by Wikipedia’s disclaimers that its articles may be “unbalanced,” “subject to remarkable oversights,” or “liable to be incomplete,” a Tennessee state court in English Mountain Spring Water Co. v. Chumley rejected Wikipedia as a reliable source altogether.5

English Mountain Spring Water concerned the statutory interpretation of a tax statute. Because Wikipedia was not in existence at the time of the statute’s enactment, the court held that it could not reflect proper legislative intent, and the court rejected the Wikipedia definition being offered.6

Similarly, a federal district court in Campbell v. Sec’y of Health and Human Servs. disregarded Wikipedia research. Campbell involved the findings of a special master under the National Childhood Vaccine Injury Act.

The special master had rejected the opinion of a party’s medical expert based upon her independent Wikipedia research. Concerned by Wikipedia’s disclaimers, and by the lack of the medical expert’s opportunity to corroborate or refute the Wikipedia research, the court held that reliance on the Wikipedia entries was “patently unfair.”7

Two recent trademark cases examining Wikipedia’s reliability have distinguished Campbell and English Mountain Spring Water. For example, in Alfa Corp. v. OAO Alfa Bank, the district court maintained that instead of disregarding questionable Wikipedia information as was done in Campbell, the solution would be to allow opposing parties to disprove the evidence.8

The court noted that a recent and highly-publicized analysis in Nature magazine had found Wikipedia’s error rate to be comparable to that of the Encyclopaedia Britannica. Noting the frequent citation of Wikipedia in judicial opinions, the court determined that “many courts do not consider it to be inherently unreliable.”9

Moreover, the Alfa court further distinguished its case by acknowledging that a historic definition (i.e., legislative intent) may not always be at issue, as it was in English Mountain Spring Water Co.

Citing the Alfa decision, the Trademark Trial and Appeal Board (“Board”), the judicial arm of the U.S. Patent and Trademark Office (“USPTO”), has held that it will consider Wikipedia evidence so long as the non-offering party has an opportunity to rebut the information by submitting counter evidence.10

In IP Carrier Consulting Group, the applicant offered a Wikipedia entry to define “Internet Service Provider” after the USPTO rejected its trademark applications for the marks IPPICS and IPPIPE on the grounds of descriptiveness.

Arguing that the most common abbreviation for “Internet Provider” is “ISP”—not “IP”— the applicant attempted to show that the “IP” prefix of its marks was not descriptive. Though recognizing that Wikipedia may contain “significant misinformation, false or debatable information,” the Board nonetheless considered the offered Wikipedia definition.11

The Board recommended, however, that “[t]he better practice with respect to Wikipedia evidence is to corroborate the information with other reliable sources, including Wikipedia sources.”12

The Board ultimately affirmed the denial of the applications because the critical issue was not whether “IP” is the most common acronym for “Internet Provider,” but whether “IP” is descriptive of internet-based services. According to the Board, the weight of the evidence showed that “IP” means “Internet Provider,” and thus the marks were descriptive.


Whether used to show trademark descriptiveness or for some other purpose, citations to Wikipedia articles have become common in judicial opinions. Trademark practitioners may want to be cautious, however, about sole reliance on Wikipedia articles.

Despite the Alfa and IP Carrier decisions, most courts have not directly addressed Wikipedia’s reliability. When in doubt, trademark attorneys may want to follow the Board’s advice and submit corroborating evidence if possible.

Originally published in IP Law 360, January 15, 2008