Nominative fair use is a legal doctrine that provides an affirmative defense to trademark infringement as enunciated by the United States Ninth Circuit, by which a person may use the trademark of another as a reference to describe the other product, or to compare it to their own. Nominative use may be considered to be either related to, or a type of “trademark fair use” (sometimes called “classic fair use” or “statutory fair use”). Jardine and the Demise of a Doctrine” by Chad J. Doellinger
All “trademark fair use” doctrines, however, are distinct from the fair use doctrine in copyright law. However, the fair use of a trademark may be protected under copyright laws depending on the complexity or creativity of the mark as a design logo. 
The nominative use test essentially states that one party may use or refer to the trademark of another if:
Furthermore, if a use is found to be nominative, then by the definition of non-trademark uses, it can not dilute the trademark.
Nominative use does not require that ownership of the trademark be acknowledged, for example by use of a sentence such as “UNIX is a registered trademark of The Open Group”. Such statements may, however, be required by the terms of a license agreement between the parties, and they may be prudent (and courteous) as a way of preventing misunderstandings or allegations of passing off.
Don’t register a domain containing a famous brand that contains a coined word such as Google, YouTube, Facebook, or Kodak, unless you plan on using it under the nominative fair use doctrine. It is very difficult to justify such a decision because coined words are entitled to strong trademark protection.
Survey says: No, don’t register the domain name if it contains a coined word and there is no fair use in the contexts of:
Examples of fair use:
mercedesforum .com: Mercedes Benz Enthusiast Forums and
Philip Morris USA Inc. v. Borut Bezjak, A Domains Limited, WIPO Case No. D2015-1128, <marlboro .party>, Denied
Azimo Ltd. v. Vladimir Zubkov, WIPO Case No. D2016-2608, <http://azimoreview .com>, Denied
http://buy-a-lexus .com and buyorleaselexus .com
The Respondent in Porsche.social argued that it planned to use the PORSCHE trademark in connection with a free community or fan site for Porsche car enthusiasts. It also stated an intent to disclaim “on every webpage” any affiliation with or authorization by Complainant, the owner of the Porsche brand. The URS Examiner held this was a fair use, finding that “[t]he use of ‘.social’ in the domain name, and the screenshot from Respondent’s website are evidence of that intent.”
The Examiner’s determination suggests the following equation:
[third party trademark] + [.social TLD] + [plans for a free fan site] = fair use (to defeat a URS complaint)
Furthermore, the Examiner found the .social TLD suffix to be evidence of intent to make a fair use.
UDRP panels have recognized fan/community sites that are clearly active and noncommercial to be fair uses (even where the second level domain is a Complainant’s trademark in its entirety). See 2001 White Castle Way, Inc. v. Glyn O. Jacobs (WIPO Case No. D2004-0001, March 26, 2004); see also WIPO UDRP guidelines. URS Procedure Rules 5.7 & 5.8 list defenses and circumstances that may refute a cybersquatting claim:
Moreover, the U.S. Court of Appeals for the Ninth Circuit has ruled that nominative fair use extends to trademarks incorporated into domain names. See Toyota Motor Sales, U.S.A., Inc. v. Farzad Tabari, et al., 610 F.3d 1171 (9th Cir. 2010).
New gTLDs and the URS (Case Brief: Porsche.social)
WIPO UDRP Overview3.0:
2.8 How do panels assess claims of nominative (fair) use by resellers or distributors?
While the following section primarily concerns cases involving “bait and switch” or other related unfair trade practices, many of the principles outlined above, especially at section 2.5 with respect to fair use, underpin the following section.
2.8.1 Panels have recognized that resellers, distributors, or service providers using a domain name containing the complainant’s trademark to undertake sales or repairs related to the complainant’s goods or services may be making abona fide offering of goods and services and thus have a legitimate interest in such domain name. Outlined in the “Oki Data test”, the following cumulative requirements will be applied in the specific conditions of a UDRP case:
The Oki Data test does not apply where any prior agreement, express or otherwise, between the parties expressly prohibits (or allows) the registration or use of domain names incorporating the complainant’s trademark.
2.8.2 Cases applying the Oki Data test usually involve a domain name comprising a trademark plus a descriptive term (e.g., “parts”, “repairs”, or “location”), whether at the second-level or the top-level. At the same time, the risk of misrepresentation has led panels to find that a respondent lacks rights or legitimate interests in cases involving a domain name identical to the complainant’s trademark. [See section 2.5.1 above.]
Panels have found that PPC websites do not normally meet the Oki Data requirements as they do not themselves directly offer the goods or services at issue. WIPO Overview of WIPO Panel Views on Selected UDRP Questions, Third Edition, (“WIPO Jurisprudential Overview 3.0”)
Registering Generic Terms
The guys who registered 100s of domains with the word Google lost their appeal on May 16, 2017. They lost a lot money trying to prove that Google had become a generic term. David Elliott, et al v. Google Inc.; case number 15-15809, in the U.S. Court of Appeals for the Ninth Circuit.
If you are a startup, find a generic or arbitrary noun. Any other choice is usually fraught with troubles. Litigation is a bad way to start a business because it saps time and capital from your business.
However, there can be minimal skirmishes with almost any choice that are usually resolved with communication and differentiation.
And if your domain contains an arbitrary or generic term that is already trademark, apply to register the mark on the basis of intent to use, before using it, so that you can resolve the trademark issues in the trademarks office instead of Federal Court.
Legal Domain Name Choices
David S. Welkowitz (2002). Trademark Dilution: Federal, State, and International Law. BNA Books (Bureau of National Affairs). p. 325. ISBN 1-57018-313-9.
Since nominative fair uses are nontrademark uses, no dilution can occur