A federal trademark registration, unlike copyrights and patents, can last indefinitely as long as the owner uses the mark continuously in commerce and makes the necessary filings with the Trademark Office to renew it. The term of a federal registration is 10 years, with 10-year renewal terms. However, between the fifth and sixth year of the initial term, the registrant must file an affidavit with the Trademark Office stating that the mark has been in continuous use. The registration will be canceled if no affidavit is filed. Arbitrary or fanciful marks are considered the strongest because they typically have no meaning in the English language, or in the context in which they are used, apart from the goods or services they denote.
Suggestive marks bring to mind attributes of a product or service without describing it.
Descriptive marks are weaker and are generally poor choices for trademarks. Finally, a generic mark is a term that has lost any trademark significance. It no longer describes the particular goods or services of a single source, but has come to be used by the public as the term describing an entire class of items. Microsoft has appealed the ruling. Trademark rights are infringed when another party uses a mark that is likely to cause consumers to be confused as to which party is the source of the goods or services in question.