Companies can use trademark words in a variety of ways. Some are just fine. For instance, using your own brand or product names is rarely going to create problems. There are instances when others can use your trademark words and you can use theirs, too. Some uses are infringement or misuse, though. Infringement or misuse usually occurs when trademark words are used in an unfair or confusing way.
Companies earn trademark in words by using them in commerce or business. Using words on packages, labels or signs; on websites or digital applications; and in advertising, marketing, promotions or other business communications establishes your rights to those words. If no one else has already established trademark, your normal and continued use of trademarked words is usually completely acceptable and good for your business.
Registering your trademark words with the US Patent and Trademark Office can help protect your right to use the words. Even if you don't register the words, you can still use them and claim infringement if it occurs. Registration is a record of your use that strengthens your ownership and use rights.
Sometimes, you can use trademark words that belong to others. These instances are called fair use. For example, you may use common words, like "apple," even though there is a company called Apple®. Fair use may also include naming another business for comparison purposes in marketing or advertising, or parodying a trademark word in art. Others may use your trademark words for the same allowable purposes.
When a company uses trademark words the wrong way, this may be infringement or misuse. Using words in a way that confuses consumers is usually not allowed. An example might be using a word to mislead consumers about the brand source of a product. Other examples might include falsely claiming something belongs to a trademark name or claiming a trademark name belongs to the wrong person or business.