Trademark distinctiveness both concepts, see Apple Corps and its disputes with Apple, Inc. If a court rules that a trademark has become "generic" through common use (such that the mark no longer performs the essential trademark function and the average consumer no longer considers that exclusive rights attach to it), the corresponding registration may also be ruled invalid. For example, the Bayer company's trademark "Aspirin" has been ruled generic in the United States, so other companies may use that name for acetylsalicylic acid as well (although it is still a trademark in Canada). Xerox for photocopiers and Band-Aid for adhesive bandages are
Trademark on colour, smell, or sound (like jingles). Trademarks which are considered offensive are often rejected according to a nation's trademark law. The term "trademark" is also used informally to refer to any distinguishing attribute by which an individual is readily identified, such as the well-known characteristics of celebrities. When a trademark is used in relation to services rather than products, it may sometimes be called a service mark, particularly in the United States. The essential function of a trademark is to exclusively identify the commercial source or origin of products or services, so a trademark, properly called, "indicates source" or