Follow the brand name with the appropriate generic. A generic is a noun that is not owned by anyone, such as "automobile." For example, a character in your novel might be thirsty for a "Coca-Cola brand soft drink." Michael Atkins, a trademark attorney, advises you follow this step, even though it might sound a little awkward. This is because a company, should its copyright be challenged, must present proof to the court that it has actively defended its brand name. One way companies do this is by writing cordial, but strongly worded letters to writers who refer to their brand as a generic. If you make this mistake, you or your editor might receive one of those letters.
Avoid referring to a brand name as a generic itself. In the past, for example, both "aspirin" and "escalator" were brand names, but their copyright owners were not vigilant enough in protecting them.
Capitalize and spell the brand name in the manner used by the copyright holder. You're not likely to misspell MasterCard, but you might forget to capitalize the "c." This is called "camel case" because the internal capital letter resembles a camel's hump. As Caleb Crain pointed out in "The New York Times Magazine," this camel case rule can be confusing, even for the most seasoned copy editor.
Use the same formatting the copyright holder does when putting a brand name into print. For example, the large bookseller should be called "Barnes & Noble," but many people don't know the company prefers an ampersand and write "Barnes and Noble." Go to the "About us" page of a company's website to see how a company refers to itself.
Attach the appropriate trademark or copyright symbol. To determine which to use (if any), take note of what the company itself uses. To insert these symbols, copy and paste them from text or, as the web site fsymbols advises, enable the number lock on your keyboard, hold down the ALT key and type 0153 for a trademark symbol or 0174 for a copyright symbol.
Avoid characterizing the brand in a manner that would be considered defamatory. If you are using a brand name in a nonfiction book and saying something that is negative, make sure you have proof of the implication you are making. When writing a fictional book, you have much more latitude. As Julie Hilden notes, it is extremely difficult to prove that harm is caused by the use of a brand name in a work of fiction.