The copyright law has the famous fair-use exception, where you can legally use some parts of copyrighted works without having to pay any royalties to, or ask any permission from, the copyright holder.

What about trademarks?

For example, Oracle owns the trademarks for the ZFS filesystem created by Sun Microsystems, which they've acquired. (Not sure when and who filed which trademarks.)

Does it imply that the OpenZFS / Open ZFS project is technically a trademark violation? Or is the trademark being shared by means of the CCDL the licence? Or do they actually have some kind of a special agreement?

What if I want to register a personal domain name like zfs.example. (either in a global TLD or a country-code TLD) to blog about my use of ZFS; would that be a violation of the trademark? What if I sell ads for products unrelated to filesystems (but related to computers)? What if I let anyone buy any kind of ad, which may include ads for computer products and filesystems? (If you come from the assumption that ZFS trademark is invalid, what would be the case if it was not?)

P.S. The was a similar case in regards to the ssh graphic trademark and OpenSSH, however, in that instance the consensus was that the trademark was simply invalid due to a whole combination of reasons. Is the ZFS trademark, perhaps, also invalid?

  • Are you interested in an answer for a specific jurisdiction?
    – apsillers
    Oct 7, 2015 at 15:14
  • @apsillers, this question potentially spans multiple jurisdictions even in its most basic interpretation, as we mention ccTLDs here
    – cnst
    Oct 10, 2015 at 2:00

3 Answers 3


Just assuming for the sake of this particular answer that everything happens in the U.S.:

I'm not sure about the particular example of Open ZFS. The registration in the USPTO Records is in Oracle's name. Using OpenZFS for distributing the same kind of software as the now closed-source ZFS would seem to be infringing to me absent a license. Maybe Oracle just tolerates the use of the "ZFS" component by third-parties since they decided at some point to license the software under an open source license. In that case, they may have a dilution (http://www.inta.org/TrademarkBasics/FactSheets/Pages/TrademarkDilution.aspx) problem and the mark may be invalid. If the mark is invalid, anybody can pretty much do whatever they want with it.

That said, assuming for sake of discussion that the mark is valid, there is indeed such a thing that is similar to the copyright fair use in trademarks (in the U.S. at least). It's called "nominative fair use". You can read more about it here: http://www.inta.org/TrademarkBasics/FactSheets/Pages/FairUse.aspx

Bottom line is that under the nominative fair use doctrine it's generally ok for party A to use party B's trademark to refer to whatever party B is doing, even to sell products and services related to whatever party B is doing. As per the INTA document I just linked above, its for example ok to "use “iPhone” in non-stylized form on packaging for phone cases to indicate that it is usable with iPhone 6."

Having a website (even with third-party ads) that discuss ZFS-related matters is similar to the iPhone example in my mind. Having a domain name that contains the mark seems riskier, but it's not necessarily downright forbidden. See: http://itlaw.wikia.com/wiki/Toyota_Motor_Sales,_U.S.A._v._Tabari

  • Good answer, thanks! However, it seems like your inta.org links don't show any useful content, possibly requiring registration and membership for access.
    – cnst
    Sep 9, 2017 at 22:02

There really isn't such a thing as "fair use" of a trademark as the term is used in copyright. What the court's call "Fair use" in trademark is where one uses another's mark to describe another's products. I can use the Microsoft Windows trademark to refer to Microsoft Windows. The reality here is that the effectively the same restrictions apply to the owner of the mark as to others using the mark.

The key thing about trademarks is confusion. You cannot use another's mark when it causes confusion.

If ZFS is a trademark, is OpenZFS infringement? Possibly—possibly not. The only way to know would be to register OpenZFS and see. Factors going against you here would be the closeness of the two marks. Going for you, is few people would know what ZFS is.

  • 1
    I do not think an examiner at the USPTO deeming that it is/isn't too close to register is anywhere near the equivalent to legal advice on the likelihood of getting sued and loosing. Also, I haven't heard of ZFS but I do not buy/use anything in that product category. How well known it is among those buyers is probably more important. Mar 25, 2019 at 23:48

The other key limitation here is that trademarks are only protected for their use in trade. If a website called "zfs.example" was used to discuss examples of the use of ZFS, but did not charge, and was not selling or promoting the sale of any goods or services, then it is not an infringement because that is not what a trademark protects against.

I am basing this largely on my knowledge of US law, but I understand that on this point trademark law is generally similar in all countries. Of course, i am not a lawyer, and this is not to be taken as legal advice.


According to the Wikipedia article,

Infringement may occur when one party, the "infringer", uses a trademark which is identical or confusingly similar to a trademark owned by another party, in relation to products or services which are identical or similar to the products or services which the registration covers.

According to Harvard's Overview of Trademark Law

If a party owns the rights to a particular trademark, that party can sue subsequent parties for trademark infringement. 15 U.S.C. §§ 1114, 1125. The standard is "likelihood of confusion." To be more specific, the use of a trademark in connection with the sale of a good constitutes infringement if it is likely to cause consumer confusion as to the source of those goods or as to the sponsorship or approval of such goods. In deciding whether consumers are likely to be confused, the courts will typically look to a number of factors, including: (1) the strength of the mark; (2) the proximity of the goods; (3) the similarity of the marks; (4) evidence of actual confusion; (5) the similarity of marketing channels used; (6) the degree of caution exercised by the typical purchaser; (7) the defendant's intent. Polaroid Corp. v. Polarad Elect. Corp., 287 F.2d 492 (2d Cir.), cert. denied, 368 U.S. 820 (1961).

So, for example, the use of an identical mark on the same product would clearly constitute infringement. If I manufacture and sell computers using the mark "Apple," my use of that mark will likely cause confusion among consumers, since they may be misled into thinking that the computers are made by Apple Computer, Inc. Using a very similar mark on the same product may also give rise to a claim of infringement, if the marks are close enough in sound, appearance, or meaning so as to cause confusion. So, for example, "Applet" computers may be off-limits; perhaps also "Apricot." On the other end of the spectrum, using the same term on a completely unrelated product will not likely give rise to an infringement claim. Thus, Apple Computer and Apple Records can peacefully co-exist, since consumers are not likely to think that the computers are being made by the record company, or vice versa.

I am not a lawyer. But from the above, and from other sources, I take it that the use of of a trademark by someone not the owner to refer to or describe or discuss the trademarked goods (or services), without offering those or similar goods for sale mis not a use "in trade" and therefore is not an infringement, even if the publication contains advertisements for other, unrelated, goods or services.

For example, If I want to post a web page with a course nof instruction about how to use the MS-Windows API, and I use the trademark "MS-Windows" and perhaps other trademarks to identify windows, and if I make it clear that I am not the creator or owner of Windows, then even if the page also contains ads, say for vacation homes, my use of the trademarks is not "use in trade" and so is not an infringement.

  • Of course, and that's part of the reason why I mentioned selling ads in the question. Does that make the website engage in trade?
    – cnst
    Nov 17, 2018 at 1:46
  • @cnst: Unless it is selling or advertising products that are the same as or similar to the trademarked ones, or it implies that it is sponsored or endorsed by the trademark holder, i don't think it is using the trademarks in trade, and so it is not infringing. See the edit to my answer for more detail. Nov 18, 2018 at 2:04

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